Talk to me about ratings please

I’m not formally taught, didn’t play in school and have just learned by playing online as an adult. I play some games where I’m really happy with moves I’ve made and some games I’m disgusted I fell for what should have been easily identified traps or setups. I’m currently rated around 1700 on Lichess and 1400 on Chess.com. Both are rapid (10+0) ratings.

While I know I can improve and bought books recently to do just that, I also feel like I’m generally playing better than I ever have but my Lichess rating is significantly lower than the highest I’ve hit which was 1863 in 2016. I t makes very little sense to me that I was better than I currently am back then. So I am left thinking that more people have started playing chess and the online ratings are therefore skewed as a result, but I can’t exactly figure that out.

Can someone explain what might be happening? It’s not that big of a deal, but I would like to use ratings to start setting learning goals but feel they may not be the best benchmark if the scale fluctuates.

Thoughts?