Doug64 Well, as you said, travel predates GPS by a couple of millennia, so travelling without it is certainly possible; and perhaps more enjoyable, depending on the circumstances. But,
as a matter of personal preference, GPS is preferable, for me.
FWIW, I've been to every city you mention, with the exception of Wroclaw, and never felt desperately lost, with or without GPS (although, interestingly, I've purchased my first GPS in Paris -- a Garmin eTrex, 21 years ago -- when I took a wrong turn which made a short afternoon stroll into a much longer one. Not a big deal, mind you -- Paris is a great city). This being said, we could never have found our AirBnB in Tokyo without electronics (no street number, basically no street name and if there are, very difficult to understand). And I mentioned the Beijing example because even a taxicab driver couldn't find the place where we wanted to go. Try (Tokyo, Bejing), Seoul, Istanbul or even Athens without a GPS and the lack of information will likely limit your freedom to explore. A GPS is like the rope that spelunkers use to find their way back, out of unfamiliar environments. Without it, you are less likely to explore as much. In my case, having a GPS, or now a GPS enabled phone has allowed me to wander out of the hotel without worrying about finding my way back. And to chuckle a couple of times (in China again) when the locals give you polite, but woefully inaccurate directions, which could be on purpose, mind you
.
We sail -- well, we did prior to COVID -- and in the early days it meant a sextant at sea and bearing compass + tedious (and hazardous) calculations when close to shore, to plot a route. I know some nostalgic people who regret this "simpler" time, but the fact is that there were many more shipwrecks back then. GPS may not be essential, but certainly more reasonable.
Your approach is perhaps the best. i.e. navigate with minimal guidance in the knowledge that if needed, you can use your phone to find your way.
(but I still think that the OP's alternatives are either city maps, a smartphone, or learning to appreciate serendipity, whatever form it may take