They don't really need to change the battle system or make it more dynamic, just look at Persona 5 a GOTY nominee and that combat similar to Pokemon, and it was praised for its turn based combat. The battles were more interactive and flashy than a Pokemon game. GF just needs to do something similar.
Also if you want to make new players at ease, just change some the competitive mechanics to be more accessible to newer players without getting rid of them and it would also implement them into the main story giving the gameplay in story mode more depth.
For example if I want a EV trained Decidueye with max Attack and Speed I have to train it by battling Pokemon that give those specific EVs (and use a power item to be done quicker) but that's almost impossible in the mainline story because its time consuming and some for resources aren't available to do this and casual players don't experience this cool mechanic (which is like special training).
This is and idea I came up with that could help make it easier for newer players.
- Levelling up a Pokemon won't increase stats, its stats will remain the same even when level 50.
- Levelling up instead gives the Pokemon EVs after it levels up which the trainer decides which stat they want to invest the EVs in but the Pokemon doesn't need to battle specific Pokemon to gain these points. Once a Pokemon levels up it gains 10 EVs for each level (this also doesn't change anything to make Pokebank EV trained Pokemon unusable). And newly hatched or caught Pokemon would have 8 extra EVs since Pokemon have a total of 508 obtainable EVs.
- Only Max of 252 EVs is allowed to be invested into 1 stat.
- EV investment is would be reset if player is not satisfied with the distribution or wants to change it since the Pokemon evolved and would benefit with a different distribution.
- Pokemon level cap at 60 (all EVswould be gained by level 50).
- Levelling up still helps a Pokemon learn new moves and evolve.
- Bottle caps are now usable at lvl 60.
- NPC trainers would also have their Pokemon invested with EVs.
So say you catch a Pidgey at level 5 it will have 58 EVs available for the player to invest and each time it levels up it gets another 10. Now if the play wants they could just invest it in attack only but as I suggested these EVs will be invested the NPCs Pokemon. So you go up against another Pidgey but that EVs have been distrubted much more evenly to making the players Pidgey inferior since the NPC has better EV distribution. This would make the player think a little to what they want their Pokemon to be, a fast attacker, tank attacker, tanky staller etc.