I feel you, I hate being in a situation where I have to upgrade. Mostly because it means my planning failed. At the risk of being the curmudgeon, 2015 was almost 6 years ago. 16gb was fairly standard back then even if it was the ceiling for macs.
It sounds more like a swap problem. Not sure how much free space you have, but it should push bits out of ram and into the swapfile when you're nearing 100% and that should mitigate freezing as long as your drives aren't close to full.
If your storage is degraded for whatever reason, you may consider getting some external TB drives and remapping the swap assignment. It's messy and potentially fragile, but could save you buying new shit.
stackodev960428d@SortOfTested I suppose I should look into that. I use the Mac for light work and occasional gaming. Mostly for writing. I had no idea Audacity would be such a dog on it, though. I did take the Mac in to the Genius Bar a while back to show them how poorly it was performing. They didn't offer much in the way of help.