alt Hacker News> But until then it's a long term cost optimization with really high upfront capital expenditure and risk.
The upfront capex does not need to be that high, unless you're running your own AI models. Other than leasing new ones, as a sibling comment stated, you can buy used. You can get a solid Dell 2U with a full service contract (3 years) for ~$5-10K depending on CPU / memory / storage configuration. Or if you don't mind going older - because honestly, most webapps aren't doing anything compute-heavy - you can drop that to < $1K/node. Replacement parts for those are cheap, so buy an extra of everything.
And if each of your clients is in the Healthcare industry and dealing with end-user medical data? Or financial data? Are you prepared for appropriate data isolation/sharding and controls? Do you have a strategy for scaling database operations per client or across all clients?
It really depends on the business model as to how well you might support your own infrastructure vs. relying on a new backend instance per client in a cloud infrastructure that has already solved many of the issues at play.