Living ultra-frugal and saving as much as possible, my wife and I quit our jobs 10 years ago and have been travelling (almost) non-stop since, celebrating our 100th country 2 months ago.
Slow travel is certainly an affordable way to live. Weekly and monthly discounts on accommodation are not a joke, and reducing the number of flights you take is good for your wallet and the environment. Same with taking public transport everywhere rather than having a car. We balance short stays in expensive countries with long stays in cheap countries.
Staying in short term rentals found (mostly) on agoda, booking.com or airbnb makes bills easy because.. there are none. For phone data, we've been using esimdb.com to find the best value esims in each location. Don't use global esims, they're a waste... 10 years ago you could go without phone data but that's not the world we live in now (you save a lot more money being able to look things up on the go and finding the best value).
The best thing about full time travel is you're never stuck in a routine. As a result, the past 10 years has felt twice as long as the previous 15. Where we go to next largely depends on what deals we find, where we haven't been, but more importantly what my stomach demands.
The kiwi.com 'anywhere-to-x' flight finder is helpful, as is google flights, but that's only x-to-anywhere. Setting a max price and zooming out on map view on accommodation sites is also great for finding bargains.