Moving to Capture One or something else seems worthwhile. Tried Darktable but wasn’t a big fan.
So, you can open it in a SQLite GUI (eg sqlitebrowser.org, which I'm a dev member of) to see and/or screw with stuff?
The downside of the SQLite dB is no network editing. I’d love to be able to edit from multiple machines without a cloud subscription or super slow NFS.
You don’t need to have your photos inside the catalog either, they can be referenced externally.
If you like to maintain your own structure, you might like the Sessions feature. It’s an folder-based alternative to the monolithic catalog.
I also like the EIP package format. You can package an image into a zip of the original image and all Capture One data. Then it’s just one file for your archives but everything you need is there for the future. Even if you can’t open the Capture One bits at some point, the original is still in there.
How long have you been working with Affinity? It's not Adobe's software and it's not trying to be, so there is always going to be some period of adjustment while you get used to a new way of doing things. IME, that passed very quickly, and within a few hours I was doing most basic tasks as readily in Affinity products as I would have done in CS/CC ones, but my work is usually more in Designer than Photo.
There is still quite a bit of useful functionality present in CC but missing in Affinity, which is a more serious problem for power users who have workflows and presets and plug-ins and so on set up with the Adobe products. But the Affinity suite seems to be developing rapidly, so perhaps in time this gap will close too.
Lightroom -> Capture One was an upgrade. Even when the learning curve is taken into account, I found C1 to be superior piece of software. It's faster, its color editing is better, and the default look it gives me was just better, at least for my camera.
Photoshop -> Affinity Photo was painful. I'd estimate the pain to be "moderate". It misses some features I want (color calibration targets support, some layer blending modes) and some others are not as great (no smart sharpening). Affinity UX of working with layers is surprisingly painful and the attention to detail in the UI is poor. But since 90% of my time is spent in C1 anyway, I found it tolerable.
It also has 'sessions' which are aimed at individual shoots or projects. I suspect most pros use them instead of catalogues. It's essentially a self-contained directory structure that C1 understands,