I see many comments on this subreddit saying "players are a lot better today, even in my [herald/crusader/guardian/archon/legend] bracket people pull and gank really well and itemise strongly and take advantage of timings and take objectives in the right order, it's just much harder now".
I'm sure I am not the only one in this situation, but I returned to Dota this year after a a 3-year break. I originally calibrated at 2.4k in 2015, and climbed to 5.49k before quitting in January 2019.
I returned December last year, and recalibrated at ~3.2k spending a few months goofing around and learning the changes. For context, when I left there were no neutral items, no aghanims shard, and fewer aghanims upgrades. The map was a bit different, and there were shrines instead of outposts, and roshan only dropped aegis and cheese. I think grimstroke was fairly new at the time.
I'm old and washed up, but I've still climbed to 4.3k with a 68% winrate since I started trying to climb, not playing very often. My winrate in the Legend bracket was 72%, and even higher when playing my role. The games are pretty easy, occasionally I lose due to some new game change (e.g. Leshrac aghanims is CRAZY good against PL and I had never seen it before) but that's not really a skill thing, it's a game knowledge thing.
Archon/legend/ancient 3 years ago would stack and pull and rotate (badly), they do the same today. No one really smokes. Roshan control is still not prioritised properly or aggressively. People's farming patterns and efficiency are still bad. Laning as a rusty old man in the legend bracket was so easy, ancient doesn't seem hard either. People don't focus correct heroes in fights. People copy pro builds without thinking, or don't update their build since a year or two ago and just do the same thing every game.
Nothing has really changed, and I have complete confidence that I will hit my old MMR even with more difficult life circumstances, because people are just as good/bad at Dota as ever. People know a few more game knowledge things (new heroes, items, map changes) but that hasn't resulted in increased skill.
Source: https://www.reddit.com/r/DotA2/comments/y3bksp/hot_take_players_arent_better_today_than_34_years/