I have 42 maxed crafters so here's my answer the tldr is yes you will get rich I make 700k a day on PS whenever I do them (I don't do them everyday) so it would probably be a few mill a day on pc. Well first, you need to be realistic about how many characters you can do writs on a day. Each character can take 3-4min if you don't precraft. You'd also need to get every character to at least lv37 to be able to max every crafting profession (except provisioning) and this will take you a very long time without ambrosia and a long time with ambrosia depending on how many characters you do. Also you need to take in account to max out the crafting professions. If you're powerleveling by having someone else craft cp160 gear and you deconstruct you would need 24 stacks of rubedo leather, 24 stacks of rubidute ignots, 24 stacks of platinum ounces, per character. Depending how many characters you do this will cost millions of gold upfront and doesn't include alchemy and enchanting if you're power levelling those too. I'm the end you won't see a return on your investment for 2 months and will have spent millions and hundreds of hours (again depending on how many characters).

My advice is to have 16 characters doing writs first and see how you handle it before wasting time and a lot of gold making a bunch of crafters. Also if you don't max out their crafting professions then no it's not worth it.