

The individual members of the foundation most certainly do linux dev, which benefits their specific company. Think kernel or driver adjustments or supporting newer hardware for servers/datacenters.
However, that doesnt mean its only the foundation doing the work, thats just the paid work being done. The rest is all passion projects of people
No you dont. Lineageos supports a lot of phones that are still supported by their manufactures. Hell my fp4 is still in support too, and lineageos runs fine on it :p
Youre thinking of unofficial lineageos builds and ports to non-supported-by-lineageos phones