Opinion about selfcest or mirror shipping

What do you think about it? I’m not gonna hate ppl for liking it but for me it’s kinda weird. Like it’s almost close to twincest but ppl say it’s like an alternate version of you and all that I could think of is that I can’t really see myself or my fav to like each other romantically cause it feels narcissistic. I don’t know when this started nor I fully understand but I feel like it started from the Loki series or the spiderverse thing. It’s weird but maybe I could see the appeal (cause I saw a fanart of a rare Megatron selfcest and I can’t deny two hot baddies y’now)