Disclaimer: I'm not a proponent of 1, 2, or 3x drive trains... well maybe not so much 3x now that we have 11s in the more pedestrian lines of groupsets, However, if you're trying to get your money's worth out of your 7, 8, or 9s ass end then maybe a 3x might be required. I think you should go with the simplest drivetrain that checks all your boxes, whatever that may be.
You need to know what you actually need for gearing, what you need for a shortest gear, and longest, as well as how picky you are about how close the ratios between the gears are acceptable to you. And this is all only a you thing and completely opinion based. Play with the calculator and see what you can get away with. Further it would do you well to know what ratios you spend the bulk of your time in. This is only my opinion and what works for me, in the cruising range I like a max difference between cogs to be 13 maybe 14%, also I find anything under 9% a bit of a waste. but at the extremes of the cassette I'm perfectly fine with large gaps. I mean I'll take those close ratios if I don't have to compromise on anything else, but this is a game of figuring out what compromises you can tolerate so... For me 2x drive trains work for me and my riding style. I'm picky about cadence when I'm cruising. When it comes to a steep hill (up or down) I'm much less picky so long as my highest and lowest are enough. If I was riding mountain and was all over the cassette and wanting large ratio changes all the time I'd likely go for a 1x12, but I don't ride that so I don't.
Sorry I completely didn't answer your question but I hope this helps.