Is the concept of MAD becoming obsolete?

Is the concept of MAD (Mutual Assured Destruction) https://en.wikipedia.org/wiki/Mutual_assured_destruction less applicable today compared to say 40 years ago as seen by the West? My contention is that it is. I claim that MAD is becoming obsolete in ways that favor the West.

I contend that the West has built and maintained centers of higher learning and research that has attracted the best and brightest from around the world. The student visa and other filtering processes ensure that the crème de la crème end up studying at MIT, Cambridge, Oxford and similar institutions. Institutions of this caliber are nonexistent in Russia. This “brain infrastructure”, has allowed us to innovate and push the domains of healthcare, deep space exploration, fundamental physics, electronics and software engineering beyond that of our adversaries.

How can this technological prowess not translate into effective defensive systems capable of destroying hostile nuclear and other weaponry during its flight phase if not during the launch and pre-launch phases? How hard of an engineering problem can it be in a time of war, to track, target and destroy the vast majority of hostile missile platforms whether on land (fixed or mobile), shipboard, airborne, spaceborne or under the sea? The number of such platforms to worry about is not infinite, indeed not even large.

I happen to be a technocrat and have personally worked with brilliant engineers, scientists and mathematicians from, Australia, Bangladesh, England, Germany, Israel, Japan, the US and other nations. This genetic and cultural diversity is a problem solving strength. And of course, these countries share research/technology at the nation level. Some cooperate in joint military exercises.

Although much research in the area of the EM spectrum still needs to be done, we have made great strides in exploiting sections of it.

https://apps.dtic.mil/sti/pdfs/AD1115153.pdf

https://www.militaryaerospace.com/unmanned/article/16712118/pentagon-wants-more-money-for-directedenergy-weapons-for-droneswarm-and-missile-defense

And once weapon design optimization becomes driven by artificially-intelligent “design departments”, the technological gap will widen further. All of this of course requires a continuous pipeline of quality, freedom-loving human wetware; which apparently there is a good supply of from the above listed countries. One could say this began after WWII with the German-American Aerospace Engineer, Wernher Von Braun, Adolf Busemann and others under Operation Paperclip.

I contend that although an all-out thermo-nuclear war with Russia would have a cost, it is nonetheless not mutually suicidal (as required by MAD) but winnable by the West without us needing to strike first. However, and if required, a first strike would be preferrable and less costly.

The continued advancement of an effective, multi-layered anti-ballistic/anti-hypersonic defense system of systems can be reduced to an engineering and probabilistic problem. Such a problem statement might be articulated thusly:

“In dealing with a first strike by Russia, how much and what mix of defensive weapon redundancy do we need in order to ensure the survival of 50% of the population and the survival of 50% of our offensive capability with a reliability of 90% at a 90% confidence level so that we can retaliate and destroy all of our adversary’s remaining military infrastructure within hours?”

I contend that we have the required brain power, innovation engines, money, economy, military-industrial complex and political motivation to accomplish such goals thus relegating the concept of MAD to Ronald Reagan’s “ash heap of history”.

I have to believe that Monte-Carlo and similar simulations are being conducted around the clock by defense strategists and war planners to answer this and related questions.

https://www.rand.org/content/dam/rand/pubs/research_memoranda/2008/RM3489.pdf

The challenge of course is in the construction of the proper probability density functions. But there are analytical methods to bound that problem while minimizing computational uncertainties.

If/when/since 50/50/90/90 has been achieved, we would restate for 90/90/95/99 or whatever strategic goal is deemed achievable or affordable by the relevant government(s) and/or NATO. There is an inverse relationship between these 4 values and the degree to which we would experience a nuclear winter and other environmental damage, providing even more incentive to strive for ever higher levels of military superiority.

For what it’s worth, here are a few statements at this site that do not oppose my thesis.
united states - Why does the US care so much about China's hypersonic weapons? - Politics Stack Exchange

“Historically, neither the US nor the USSR officially adopted MAD as part of their policy on nuclear weapons. The official Soviet policy was that nuclear wars were survivable and therefore winnable, which contradicts MAD. Official US policy at several times included the possibility of limited nuclear strikes that would not necessarily entail mutual destruction (e.g. "tactical" nuclear strikes to blunt potential Soviet armored advances through the Fulda Gap).”

“Firstly, the US has leaned towards the idea of developing an anti-missile shield, and withdrew from the anti-ballistic missile treaty in 2002 to enable it to pursue this goal.”

“Part of the problem with MAD is it requires the other side to be able to respond and there are ways to prevent that. It can be as simple as destroying the weapons first or preventing anyone with authority from ordering a counter strike.”

Obviously this is a national-security-sensitive subject so please do not share any classified information. But I would like to know what are the flaws in my analysis and the evidence that MAD is still relevant.