30 years is proof enough.
Just submit a few stuff. If I see a binder and carton box on my desk, I'll keep off those till the day I'm in good moods.
Quarterly statements for last 5 years, insurances, tax for last 3 etc. Then maybe a few pictures ranging the 30 years (20 total, collaged 5 per page for a total of 4 pages). Maybe make I page photos from 90s, the other 2000-2010, the other 2010 to 2020 and last 2020 to 23.
P.S: Aaaaaa and it’ll be online submission...so, just submit what the system asks.
What I wrote above was for if you were in US. But since you're outside, file I-130 online and just provide what the system asks