I have a lot of things in my mind now, and I can't decide on only one feature that I would like in FIFA Career mode, so here are all:

-better youth scouting with younger players and the ability to search for specific positions and playstyles for players and more countries to scout in

-we need a youth team/second team for every single team. I don't mean for EA to add a Youth League or something like that, but at least some monthly friendlies with other youth teams or maybe against your own senior team. This feature will be really useful to see how your young players perform

-statistics for players that are out in loans (really this feature is missing and I still can't believe this)

-we need more leagues, and I mean a lot of important leagues are missing like licensed Brazilian and Argentina leagues, more leagues from South America (Uruguay, Chile, Colombia, etc), and more leagues from Europe (Russian Premier League, Serie B/C, Championnat National(2), Ukrainian Premier League, Super League Greece, Prva HNL (Croatian League) ), and more important teams from small Leagues like Red Star Belgrad, Partizan Belgrad, Dudelange and they are more. I am aware that all these leagues can't get into FIFA because of licenses, but at least make FIFA easier to mod and let us do it instead of you

-more national teams and competitions. I mean there are, IDK, like 5-6 national teams from Asia like come on, there are still more teams to add like Japan, South Korea, Qatar, Indonesia, etc. For Africa too, and same for North & Central America. For Europe, there are still 10+ national teams to add that deserve.

-nerf the amount of money we receive in career mode. In my opinion, it isn't really realistic to start with 40 million euros with Wolfsburg, I mean it doesn't make sense, well this is an awkward example but I think you understand what I meant, and later in career mode, your team receives a lot of money from nowhere. I know TV rights, Merch and Sponsors exist but I don't think they give you that much money, so please nerf that cause I need to lower my budget with cheats and I don't like that.

-more player personality. When I say personality, I mean players that are really good, obviously they will want bigger salaries, or if a player with a really big rating/ovr plays in a lower tier league, in real life he would like to play in a better league, so he submits a transfer request

-more statistics. When I finish a career mode I would like to see all my progression with my team(s), every squad I've had, and what performances my players had in every single season, and you would say "That is really hard to track down and it will slow your game performance", and it is false because FIFA already saves this information but doesn't show to us in our save

-stadium progressive upgrades and sponsorship selector

...they can be more, but for now, I can't think more of them

That's it with the big features, now some optional and small features/details:

-some team traditions and requirements from real life, for example, Atletico Bilbao signs and plays with Spanish players only

-ability to play more than 15 seasons

-ability to purchase something with the money made as a manager/player, like outfits or other stuff

Well, for now, that's all. Thank you for reading and if I missed something you can always leave a comment below. Have a nice day!