I have met a lot of people that were touring on a hybrid bike with rear panniers and something like a handlebar bag or bikepacking handlebar harness that can hold a good size drybag up front, say 10 liters or so. If you backpacked with a 55 liter backpack, you could get by initially with rear panniers on a good rack on something like a hybrid bike.
Then if you decide you like it, in a year or two supply chains should have recovered somewhat, bikes and accessories should be more available than they are now.
I met the gal in the photo above in Nova Scotia, she was from the UK, had started her bike trip in Toronto and had been bike touring for several weeks by the time I met her.
Or, like Tyrion in post number 3 above mentioned bikepacking gear that does not need racks, can be fit to most kinds of bikes. I personally would rather carry more gear than bikepacking gear, but as a backpacker you already know how to pack light.
I prefer four panniers instead of the two pannier option that I mentioned above. In the photo below I have a pair of rear panniers (40 liters), front panniers (25 liters) and a handlebar bag (maybe 8 liters), the only thing on the rear rack is a tent pole bag. But, to start with, two panniers might work well and you can add to it later.
Don't get hung up on one or two brands of touring bikes, there have been a lot of good ones from other companies like Soma, Fuji, etc. But right now with supply chains being a mess, it is hard to find a good deal on anything. Thus, you might want to start with a low budget hybrid, then if that works out, upgrade to a purpose built touring bike in a couple years.