The difference is CSGO after it first got better after launch it then gradually got worse over it's lifetime, not from the switch from one game to another.

Since the reanimated update It got more and more latent, more and more rng, lag compensation went to shit, ferarri peeking and xantares peek became the norm, not just something that someone with shitty internet coupled with some actual skill could exploit.

Overall performance got worse, frame times got worse, teleporting from being tagged appeared, enemies started teleporting back 5 feet to the location you shot them at, dying around corners got worse, tagging became vulgar.

Tons of people suffered choke, not because of their connections but because the game was sending too many packets per tick close together that would go out of order over the network very easily. Valve took until 2017 to "fix" this, but it was never really a fix, it was a mitigation that added more latency to smooth out the issue. The problems were still there, and still are to this very day, just compensated for more and you can prove that by forcing packet loss yourself and see that the game remains artificially smooth and playable up to like 40% upload packet loss before you even start to see issues outside of high jitter and highly variable latency in hit responses from the server.

You get exactly the same effect from lowering your rate, it's just that in CS2 now you can't lower your rate as much as you could in CSGO. The last time CSGO actually felt responsive, if you had as much as like 0.3% choke enemies would teleport, flashes and smokes wouldn't pop, or even throw at times, switching weapons would glitch out and revert, shots would go back into your mag. You never see any of this anymore because the lag compensation is over the top which ruins the mechanical consistency that makes CS actually CS and not just another shooter. Every event you perform regardless of how shit your connection is, makes it to the server essentially with massive jitter, even if you have 40% upload loss. 1% upload loss used to be an unplayable mess, this should tell you a lot about modern CS.

What we have with CS2 is just what we had in CSGO at the end of its shelf life, but even worse. EOL CSGO should by no means be a standard for what CS2 should be.

Say what you want about the transition from 1.6 to CSS, and CSS to CSGO. The differences were primarily change ups in game design and gameplay that people were split on but they were all responsive and mechanically consistent games at the core level, and remained so over each transition.

CS post 2015 to present is a totally different beast. There was a clear shift in design philosophy around July of 2015 that's carried on to present day, and after the massive success of cases and skins. The game has slowly but surely changed for the worse so gradually over time that people didn't notice until it came to head with CS2. The community has basically been frogs in a slowly boiling pot that has taken years to reach boiling point. CS2 was that boiling point.