Infra should not require much in the way of redoing if it's done correctly. Foundational software's configuration like RDBMS schema, maybe, but I wouldn't classify that as infra per se.
Seriously, I'm struggling to figure out how "we have servers that run containers / applications" would need to be redone just because the application changed.
Some things that can happen: Product gets canned.
Customers want on premise in their data center.
Usage spikes are too extreme and serverless is simply the cheapest option.
I would always recommend "serverless" monolith first with the option to develop with mocks locally/offline. That's imo the best risk/effort ratio.
Seriously, I'm struggling to figure out how "we have servers that run containers / applications" would need to be redone just because the application changed.