Hi VZZZ,
I agree with you and feel your frustration. The process does not need to be this complicated or this long, but I’m not in their shoes to judge. If you were staying for an extended amount of time in the country you’re travelling to, an option would have been to apply for your passport from abroad, but I wouldn’t recommend that route as other things could go wrong with the application and it’s probably relatively a lot easier to rectify issues while in the UK.
I think it’s even worse for British citizens living overseas who have to wait without a passport in a foreign country for several weeks not knowing when will your renewed passport be returned. Sure, you can apply for an emergency travel document at the nearest embassy, but my feeling is in the case of a real emergency, those documents won’t come fast enough. Surely a better process should be put in place (perhaps something like: apply, keep old passport until the application is processed, have option of either send old passport at the final stage or have it processed at a local consulate/embassy).
Hopefully your application will be done in time, but judging from the timelines we’re seeing, I’d say definitely have a backup plan