5 second page load is not fine. Having the page load in 5 seconds is an annoying experience that causes you to lose users -- Amazon lost 1% revenue for every 100ms in page load time: https://www.gigaspaces.com/blog/amazon-found-every-100ms-of-....
That analysis is from 10 years ago. Again, the landscape is different and spending time on this is a borderline foolish discussion (interesting from a technical perspective). It matters if you are the owners of a business, in the mass-retail space. Save yourself the time, add to your features or verticals.
Yes, 5s is still fine.
It seems like your argument isn't that it's fine across the board, but rather that it's tolerable in a few circumstances. If I try and load a website that is packed with features but loads slowly and maybe has a choppy experience, I'm going to go somewhere else if I can. It's only in the few circumstances that you can't go somewhere else will you be relatively fine.
Business to business app, or sales site?
YMMV. 5 seconds could be intolerable, or a big improvement.