Allowing "small" validators

I have a more general question that might be obvious to most people.

I see that the major Cosmos chains have validators who are each “big” players. These validators have invested significantly into their infrastructure, and these are run much like a business. I can understand why, with the risk of slashing and the competitiveness to get delegator commissions.

But in general, what are the reasons why a Cosmos chain could not have even “smaller basement” operations to also run validators? It seems to be more decentralized to do this, than to have only say 10 or 20 major players (which sounds alot more like DPoS). I heard that there are performance considerations why you would not want 10,000 validators, but what if you had say 50 big ones and 150 smaller ones?

These smaller guys would still need to ensure they stay up and running and be available while they are part of the validator set, of course, to avoid slashing. But is the overlying assumption here that only one of these “bigger” validators has the infrastructure to provide this required uptime and availability?

As a very contrived example, what if these smaller guys could come on as a validator for 8 hrs in a day while they were able? As in, register as a validator at the start of that 8 hrs and then leave at the end. I realize this might be difficult/impossible as there are some restrictions to “coming and going” as a validator, such as stake remaining locked for a bonding period – I don’t quite know yet if you can “rebond” with tokens that are locked still from a previous bonding lockup period.