My small list of F1 2021 suggestions is as follows.
My Team
Provide more badge options with more customisation, for example, creating your own logo out of multiple shapes rather than just one shape and one background.
Maybe the ability to edit the logo and name of your sponsors to better suit your car. Being able to move, size and rotate your sponsor decals would be useful too. Additionally, being able to add custom text with a range of fonts to enhance the way your car looks. (A great example would be adding a website or a social media name for that extra bit of realism)
Another idea I would be very happy to see would be being able to create your own junior driver programme/academy. This could include a whole department/facility with scouts and could improve both the stats and affection (see below) of the drivers you select.
Affection: Similar to how the teams value you in a normal driver career mode, drivers in the My Team mode could have certain levels of affection for their current team and others in the championship. As mentioned before, having a driver in your driver programme can steadily increase their affection for your team and improve your chances of negotiating a contract. However, if you replace a driver or deny them a contract extension, their levels of affection for your team decrease. Additionally, keeping a successful driver on a low contract or without enough bonuses could also decrease their affection to the point where they start looking to move to a different team.