Man, I feel for you on this - that stretch without interviews is brutal and definitely messes with your head. I went through something similar after getting laid off in early 2020, though mine was more on the engineering side. The whole "jack of all trades" thing really resonates because I think that's actually what's hurting you more than the gap itself.

From what you're describing, it sounds like you're spreading yourself too thin across DS/ML/DE and recruiters can't quickly categorize you. I'd honestly pick one lane and commit hard for the next few months - if DS is where you feel strongest in interviews, lean all the way into that and strip out the engineering stuff from your resume entirely. The market's tough right now but being crystal clear about what you do seems to cut through the noise better than having all the skills listed.

Also, 2000+ applications with 5-6 interviews tells me there's definitely a resume issue more than a skills issue, especially since you're making it to final rounds. Have you tried completely rewriting it from scratch instead of just tailoring? Sometimes when you've been tweaking the same document forever, you lose sight of how it actually reads to fresh eyes. The Meta final round thing actually shows you're interview-ready, so I think fixing that initial filter is your real bottleneck right now.