Re cost cap: do we actually know that all the teams are capable of spending $140m? It’s still not ‘even’ if a handful of teams are spending 80-100m.
I get the scepticism with Ferrari - for example they didn’t anticipate either the 2009 or 2014 regulation changes well - but the most recent major change, 2017, saw their biggest jump in competitiveness in years. Add to that less focus on 2021 than the other ‘big two’, almost certainly more wind tunnel/CFD time (I’m kinda surprised they’re so keen to be 3rd this year - might be more strategic to be lower), and I’d suggest they have a good shot.
The X factor with them (and everyone else) is the PU. The chassis regs are more restrictive so the PU will be a big differentiator and the PUs are locked after the start of the 2022. Will Ferrari go big and risk messing it up? High risk, high reward. Likewise for the Renault. I don’t believe the RB engine will receive any upgrades after this year and you’d imagine Mercedes will iterate on the solid base they have, but it may well all come down to engines.
Presuming all the engines - and therefore the cars - are very close, let’s say top 10 are covered by half a second, then the driver also becomes a bigger part of the package. We regularly see one driver two, three, four tenths ahead of their teammate and that could be enough for several places on the grid. We don’t know all the lineups yet but, again, I would guess that Ferrari’s will be among the strongest. A Max/Russell Mercedes combo (Zack Brown’s speculation) might also be pretty competitive!