I never got on with GO as much as I did with Source, but I can see from this thread that Source wasn't universally liked. Source was in my blood throughout my early to late teens and in terms of people I know I was probably the best at any of the CS games - on a global level not a patch on a reasonable percentage of the player base. Source was nearly exclusively the only game I played, get home from school and do nothing else, weekends were a case of wake up and play Source until I went to bed again. I was part of a couple of amateur clans, nothing major though and never went to proper tournaments.
I'm not quite old enough to have been playing online games when 1.5 and 1.6 were the in thing, but I've dabbled in them. At college my group had a small out-building which had 8-10 old PCs inside and was originally set up to learn about hardware, but the lecturer gave up with that when he realised we all knew as much about hardware as he did. This was 2008-2010, but these computers were just about comfortable on Windows XP and would run 1.6 at 30fps if you were lucky and had the computer with the best components in the room. Think single core Pentium processors, just enough RAM to meet the minimum requirements and a very primitive graphics card if you could find one that hadn't been used as a weapon, but likely onboard graphics. We'd spend all of our free time in there having our own LAN party because there was no internet connection.
GO just started to get irritating with too many screaming kids - many of them Slavic. Sometimes you could even hear kids arguing with their parents about playing one more game. If you didn't have that you would have the opposite end of the spectrum - older people at GN level try-harding something chronic and abusing everyone else on the team for not doing exactly what they want. You also had the people who would join the 'competitive' games and just do their own thing or quit the match part way through. I guess it'll be a similar thing in other games. This is all before it became F2P, I've no idea what the game is like now.
However, apart from very rarely jumping on Source to play public servers (strangely age hasn't impacted my aim/reactions too much as I keep getting accused of hacking with my 180 insta-headshots) I don't play any of Counter-Strike games now.