My workplace switched from G Suite to all MS a while back. I was livid at first. MS Excel does have some good features that Sheets doesn't, and some of their formulas can be better functionally. But Google understands user experience better and it definitely runs more efficiently than Excel. Like, Excel, This workbook isn't set to share yet, it's entirely local. Why is every other window of Excel also updating every time I change something? They aren't affected!
Anyway, if possible, when I'm working on a really chunky workbook, if possible I'll do all the work offline in the app and everything else open in the browser. If I have to add it to a shared sheet, I'll just paste it in when I'm done and know it works. I work with excel lot, but it's mostly data sifting and I tend to use Excel in ways it was not designed for, so my formulas can get out of hand sometimes and be a bit much on larger sheets.
Oof. Yeah... Sometimes there's just no getting around it. That's rough. I've had some that when I was working on them I just knew that it should take 5 minutes but will end up being 30 because every input means I wait 5 minutes for it to catch up. We also have some that are used and continuously updated every day. I was finally able to convince them to archive old ones and get a new sheet every quarter.