I follow a lot of sports, but I watch very few (regularly).
Soccer is still my #1, but I don't find it as entertaining as I used to, for three major reasons:
1) Less variety in tactics, and less identifiable positions/roles/styles. Expecting attacking players to constantly press means they tend to be more well-rounded, and you get less "pure", specialized offensive geniuses. Some of the more dogmatic, egotistical modern managers would probably bench some of the lazier, less-discipled all-time magicians like Romario and Zidane.
"True" attacking midfielders and second strikers seem to be steadily dying out, and is there a single top player nowadays who's primarily considered a sweeper, wingback or wide midfielder? Guys like that were in regular Ballon d'Or contention not that long ago.
People will claim this is simply a case of relabeling sweepers as center backs, wingbacks as fullbacks, wide midfielders as wingers, attacking midfielders as central midfielders and second strikers as center forwards; but I'm not convinced.
I was a critic of them when they were more popular, but now I kinda miss the incessant long shots, and the subsequent high-scoring midfielders, or the constant long passes/high crosses, their masters, and the aerial specialists who thrived off them.
2) Poorly implemented VAR. I always supported the introduction of VAR, as I believed a marginally slower game was a fair price to pay for 99% accuracy on big decisions. Instead, we got a substantially slower game with like 80% accuracy on big decisions. In 2020, I told myself "VAR is still young, it'll be refined and optimized soon". We're now coming up to 2025; it shouldn't still be this clunky.
Having said that; I'm still generally a fan of tech in soccer; goal line tech, automated offside, connected ball tech... even VAR (theoretically).
3) Less talent concentration. We're not quite at early 2000s level of fragmentation, but when was the last time this many elite players were playing outside the big 5 leagues? Just between the Saudi league and the MLS, there are probably at least 20 guys good enough to start in the Champions League round of 16. There's this idea that it's just a phase; that the Saudi league is just the new Chinese league; they'll throw money at it for a few years and if it doesn't gain traction, they'll abandon the project... but that isn't some law of nature, the Chinese have traditional power, they don't need soft power. The Saudis need to find new sources of revenue, otherwise they're fucked once the oil runs out. Plus, soccer is the most popular sport in Saudi; that's not the case in China.
Having said all that, soccer has evolved in a couple of ways I like:
1) Organizationally, I think expanding and introducing major international/continental competitions is an overall positive; it's further unified the game and eliminated BS friendlies (though fixture congestion is obviously an issue.)
In particular, the UEFA Nations League seems to have created an iron-sharpens-iron effect, without it, I'm not sure we'd have seen the current Spain team, or that great ~2021 Belgium side.
2) On the field, it seems like goalkeepers are generally better with the ball at their feet than they were 10 years ago. As good as they were at shot-stopping; the more traditional, limited guys like Joe Hart and David de Gea aren't starting at big clubs anymore, though I sometimes wonder whether the superior on-ball ability of guys like Ederson and Onana is actually worth their inferior shot-stopping.
My #2 is MMA; I support all the changes to the unified rules over the last 10 years or so.
My #3 is boxing; the Saudis have improved matchmaking.