My background is consulting and earlier-stage startups in the UK which may mean we’re in a different environment to what you’re used to, but the teams are often lean, and sometimes strained by the time we’re out to hire.
Sourcing and screening often starts a few weeks/months before but generally we move quite quickly through technical to offer stages - I think its healthy and fair for both parties to keep expect these final stages around 1-2 weeks.
Interviewing takes quite a bit of time and energy from the tech team and can impact team health, delivery, and ultimately bottom line - where our salaries come from.
If we’re in the fortunate position to have a final candidate (or two - three), theres going to be an exploding offer because we need to get back to work, and we need to let other candidates know to move on.
As a candidate its very fair to line up your interviews with a few companies and tell them you would like to make a decision by a particular date. If they cant accommodate you or extend an offer with a deadline prior to that, its on them. In my last job hunt no company turned down this request and two adjusted their processes to accommodate it.