The budget cap is just a little over the current Haas budget. Personally I don’t find the prospect of watching a race with 10 Haas level teams in it to be a particularly compelling idea. I’m also not that excited about the idea of constructor innovation being limited to what you can achieve with a Haas budget.
The budget cap is probably the bluntest tool available for addressing constructor performance balancing. For example, the current chassis rules make aero incredibly complex to design (which is expensive), and makes close racing impossible (because of all the dirty air). They would have been better off simplifying those rules (and maybe bringing back ground effect). Look at how well Racing Point performed last weekend, they nearly got a podium. The only significant change they made was copying the Mercedes 2019 aero kit.
Sealed ground effect will probably not return to F1, not for performance reasons but safety. Introducing the seal greatly increases downforce but once it is broken, the dropoff is incredible. Maintaining that would be nearly impossible with surface imperfections and debris on the track.
Regarding ground effect, the new 2021 regs have already brought it back. They’ve simplified the wing designs, and moved a lot of the downforce to ground effect. It’s not the same level of ground effect that F1 had in the 70s/80s, it’s more like the current IndyCar ground effect design. But the result from a following car perspective is the same. Moving the downforce from wake generating bodywork to under the chassis. However the overall effect is less downforce and therefore slower cars on circuit.
My mistake when you mentioned ground effect, I thought you meant sealed (skirts and fans). The ground effect you mean is already a thing in present F1 thanks to diffusers. The new rules have just made the diffuser bigger and simplified the front and rear wings.
[1] https://www.racefans.net/2019/10/07/todt-admits-2021-budget-...
[2] https://www.racefans.net/2019/12/27/the-cost-of-f1-2019-team...
[3] https://www.racefans.net/2020/01/02/the-cost-of-f1-2019-part...
You can’t figure out exactly what teams that’s going to hit, because publicly available finances don’t have enough detail. But it’s either going to bring spending more or less in line with Haas or Racing Point, who are both pretty close in terms of spending anyway. The reason McLaren (a relatively big spending team) are so publicly in favour of it is that they’ve had some pretty serious financial trouble going on recently.
[0]: https://www.formula1.com/en/latest/article.breaking-news-f1-...
Somebody will optimize for the engine, somebody for the aerodynamics, somebody for the suspensions, somebody for the tires (buy them from whoever they want) etc. I guess very few will spend much on the driver.
At the beginning they'll be slower than the current cars (which are only marginally faster than the v10s of 2004) but year after year they'll improve new areas of the design and get fast again. I expect a lot of technical drama and very different solutions. It's going to be back to the 70x and 80s with today's technology and processes.
Budget caps seems like a cop-out though, as eventually the budgetary rules inherit all the complexity in the current technical rules.
I think some kind of FRAND forced tech licensing / transfer + shared manufacturing would be an interesting solution. Whereby a hyper-optimized solution by a leading team can be licenses (or is outright open sourced) for the next season. And similarly, where all builders have access to a neutral manufacturing facility (a la TSMC).
And people who like to think about possible unfairness could argue that manufacturers build about 100 engines per season, test them, then pick the ones to keep, the ones to give to customers and the ones that turned out not to be good enough for racing. It's hard to get the very best engine if you are only a customer and you're really competing against the manufacturer and not only an appearance.