Depends on where you live. There are definitely certain lakes in cali that are basically swimbait conventions year round lol.
No one really has the answers because it’s all anecdotal but I’d assume if there was some sort of graph measured with stats it would probably show that it has gotten a bit harder over the past 15 years. Then there is always the natural cycles of the lakes and ponds that happen so that makes it almost impossible to narrow down which factors are actually making the bite tougher. I can say this though, I truely believe some of the lakes I used to fish at are some of the most pressured lakes in the U.S. (you can go at any given time regardless of time of year and pick out 10+ guys throwing big baits) and there are still guys that slay and stick out above the rest.