I think you may be in the minority on that. Actually I think a lot of people have felt that Legends Arceus has reinvigorated the series and has given the series a much needed evolution. Interesting to hear that you didn't like Legends, you might want to elaborate on why.
As for me in particular, I didn't like the direction Pokemon was going in from XY to LGPE (and even BW played a part in this direction as well, but I did like BW2 as that felt like it had more in common with previous games). The games were getting too linear, too easy/casual focused, and too devoid of content. SwSh and especially LA have felt like a reversal of this direction though. The games have started opening up and transitioning to open world and they seem to be trying to balance the difficulty for both casual and hardcore players now. The content could still use some improvement, but everything else is an improvement over the 3DS era and even the DS era in some ways. And it's too early to tell, but SV seem like they're taking this even further with the game being open world (hopefully that brings with it even more exciting evolutions such as being able to go anywhere you want or fight any gym leader you want from the start). So no, I feel the opposite, I think Pokemon has actually gained a little bit of its appeal back recently.