About 2020 it was a matter of engine "grey" tricks banned, they lacked 50bhp during the whole season.
About 2021 if you could read the technical rules you could understand that they can just work on a single element, they choose rear suspensions.
Renault has same Ferrari limitations don't know where they will use tokens.
MCL due to the engine change will have pratically a new car/chassis.
RP will have 2020 Mercedes W11 rear suspension for free so they can use the two tokens elsewhere.
These are the rules, Ferrari from January 1st 2021 is 100% working on 2022 car.
It's not everything related to budget, and RP got W10 chassis for freee .