1. 1Password apparently works fine with WINE, but I haven't used it myself.
2. Spotify will still receive updates for Linux, they just don't have a dedicated Linux developer on it anymore. On my machine it still works fine.
3. I prefer GoodBudget, which IMHO is much better than YNAB, especially when it comes to their iOS/Android apps. The desktop client just runs in the browser. Also, I've heard YNAB will be discontinuing their desktop apps?
4. There's https://github.com/odeke-em/drive, a fork of the official drive client, and it's still being actively developed.
5. Haven't used Alfred, but you can get some of it's features using other tools, e.g. indexed search using Tracker, clipboard history using Diodon, and perhaps some other things. However you are right that you can't get the kind of polished automation Alfred seems to provide. Rather, you'll have to write shell scripts and use the commandline tools to get what you want. Absolutely everything is possible, but it'll feel a bit like using lots of duct tape at first.
Note: I'm not saying you should switch right away (1). But I used Linux (Ubuntu) full-time for work and at home for the last 5 years and I was able to do everything with very few exceptions (2). Most peripherals that I bought just worked out of the box. Going Linux full-time is 100% doable.
Also, with so many apps running in the browser (or on Electron) the choice of OS matters less every year.
(1) in fact, I'll probably get a Mac myself this year for developing iOS apps.
(2) Only exception: Windows VM for Microsoft Word/Excel/Powerpoint & iTunes for iPhone syncing. All other software ran in WINE or had a reasonable Linux alternatives.