It may not be the longest story line in a pokemon game but the seemingly faster pace doesn't really detract from the entertainment value for me. I still completely enjoy playing the game and I find myself getting more invested in the new mechanics than some of the previous games. The world looks cool and it's pretty fun just to hop on a bike and cruise around.
The ability to dodge just about every random tall grass pokemon battle has it's ups and downs. I think it speeds up pace because now you can pretty much see 99% of battles coming and if you really want you can dodge at least 75% of them completely. It is nice being able to zip through an area full of grass and not encounter 50 lvl5 dinks that you 1 shot and gain 1exp from that waste a bunch of time. I also like being able to walk up to grass and target specific pokemon at will. On that topic also, the random very strong pokemon mechanic is cool to me and I think it makes the level cap for catching acceptable and balanced.
Dynamaxing is interesting overall and I personally see it as a fun wow factor used in the game's world as a crowd pleaser for stadium battles. For my own play I find it cool seeing my Pikachu become the size of a large building and it's a unique mechanic to utilize for timing in a battle to gain an edge, sort of like what mega evolutions were but for short bursts and with really big explosions.