I think iOS 14, and/or the latest Safari has gotten much more aggressive about opening URLs in the associated app. I had to throw away the Wikipedia app on my iPad, because Safari kept throwing pages to it - it’s pretty, but it doesn’t have tabs. If I wanted to have several Wikipedia pages open at once, it was a painful to have the app that does tabs well (Safari) defer to the app that doesn’t do tabs at all.
I also find that if the last thing I did in Safari (most recent tab or URL it’s seen) was a site that has an associated app (like wiki or YouTube), when I switch back to Safari, it will “helpfully” reopen that same URL in the associated app. This was what got me to tops out the otherwise fine Wikipedia app - be reading, say, MacRumors, open up a new tab to look up something in Wikipedia, switch to, say, messages for a second, switch back to Safari, and SURPRISE!, you’re taking a trip to the Wikipedia app because Safari detected a URL - never mind that you already got the bit of info you wanted and your very next step was going to be to close the Wikipedia tab.
I wish iOS / iPadOS 14 had a page in settings to control which apps were allowed to grab control of their various URLs, I’d neuter a bunch of them.