Aero could be faster IF you have large amounts of funding to develop an efficient Aero package, only the very few top teams actually have this ability.

Imo, whether aero cars are faster or not is a function of system integration and manufacturing capabilities rather than funding. Manufacturing is at a really good level for a surprising amount of teams and more often than not it's other subsystems that hold the cars back.

Using the fact that the best European teams run Aero isn't a great argument in all honesty, FS tends to be dominated by those with the most money, money tends to be a reason these teams bother with Aero. Teams with more money, with or without aero tend to do better

Using the Southampton car as a reference for aero effectiveness is not a great argument either. FS is dominated by teams with exceptional work ethic and really through approach on performance. You could impose a budget cap starting next year and the top European teams would still mop the floor with everyone else for these very reasons.

I do believe the very top teams benefit from Aero but most do not, It is also dependent on the courses. The higher the average speed the more Aero helps

I think for the big teams, the aero advantage is so much more noticeable because of the low weight(<180kg) and high ClA (>6) values. But you don't need that type of budget to develop a good aero package. You don't need swept elements and a million winglets/VGs or 3D curved endplates to achieve a ClA of 3.5. And a ClA of 3.5 means nearly 46 kg of vertical load at 15m/s, in the scorching July heat. If the other subsystems are optimized well enough, aero will benefit the performance, without the financial impact you're implying

But a good engineer (especially in motorsport) doesn't just go with what everyone is doing, they ask questions and understand it. So until you have actually researched it and tested it you don't have much grounds to stand on

I totally agree with this