I am going hardcore mode, no play services, trying to install as much open source as possible with as little apps from Aurora as possible, at home that's fine, but I can tell you that traveling is a nightmare.
Thank god that I have Proton Drive for cloud backup of pictures, but I have no way of paying if my wallet is stolen.
I have to find my way with open street map, which is completely doable on foot, but as soon as transports is involved, it depends.
Also it's very difficult to find new places to visit, I usually go on Google Maps web to get suggestions of places to visit which I then search in open street maps.
Finally, depending on the public transport apps and country, I can simply not use them, or I am one thing away from not being able to use them anymore and having to do everything on foot till the end of the trip.
It works, but for most folks I would really not recommend going that way, go the play services route instead, because it is a constant challenge and I am always one incident away from being stuck in the country with no money, transport or places to sleep at.