I got to say, I love this saying.
All things being equal, dot dot dot.
But all things are never equal. You're rarely comparing apples to apples.
Prioritising accessibility work would be simple if all things were equal. You'd just rank issues by importance and work down the list. Easy.
But what's importance? It's rarely one thing. It's rather three or four things squeezed into that one word.
You have impact. How many users does this block and how badly? Then you're looking at effort. A two-line fix and a six-week refactor aren't the same. And there's also timing. Is the affected user flow being rebuilt next sprint anyway?
When you pull on any one of these, the others will shift.
A low-impact issue that takes 20 minutes to fix might jump the queue ahead of a high-impact issue that requires rethinking your navigation. And you're not being lazy here. You're just doing a good job with triage.
So when people say "prioritise by importance," what they mean, without knowing probably, is compare things that aren't really comparable. It's apples to oranges. And sometimes you're weighing that apple against a spreadsheet, a release date, someone's gut feeling and a support ticket.
I have no clean formula for you.
Prioritisation is a judgment call you make with incomplete information on a timeline that's already too short.
All things are never equal. That's exactly why prioritising is hard.