If you have an application/architecture which can benefit from 64GB or more ram, or 32 or more cores, the payoff time compared to running on AWS is probably single digit months. Perhaps twice that for some of the smaller and hungrier wannabe hyperscalers.

From my perspective and this is based on every single project I've worked on in the last 20 or 25 years, the development velocity you can get with a tiny team building a monolith that can be reasoned about successfully by non genius level developers makes it totally worth going all in on a single server monolith. You do need to acknowledge that you'll rip and replace it all when(if) you start to approach the level of growth that justifies having a development team of at least several dozen, who'll need to split into teams of 2-5 working of sub components to be able to have the entire team work well. But until you can afford to pay for that team of 30 or 50 or more devs, stick with the single server approach.