It all depends on how much you do yourself. If you're going to do your own marketing, websites, handling bookings, organisation of cleaners, repairs, maintenance, etc., then it can be a very good business, but that's what it is - a business. Any business takes a lot of time and effort to run.
If you don't want to deal with that, and want local agents to do the marketing, bookings admin, cleaning & maintenance, you'll be paying a small fortune to them to do all that. Typically 25% of income for the marketing/management alone, plus wages for the cleaners and maintenance people
Plus costs of replacing fixtures & fittings, soft furnishings, bedding & linen, welcome packs, etc etc. Plus of course, management fees of any complex it's based on for maintaining communal areas, freehold building repairs, swimming pool maintenance etc etc.
If you need to borrow and pay interest, there'll be little "profit" left, even less after agents and other costs if you don't manage and clean it yourself!
Lots of people make good money out of marketing, managing, cleaning and maintaining other peoples' holiday lets!!!