If you're about to have an explosive turn where you make a ton of tokens, be they creature of artifacts, drop Haliya first to rack up the lifegain
"But I think a really key factor would be social media, and its impact on all collectibles in the last 20 years." Considering the growth of the subreddit from under 1,000 subscribers in early 2021 to almost 30,000 now, as well as amassing 150k weekly visitors, it's clear that this group of collectors has expanded alongside the surge in Pokmon cards
It's cheap and splashable so it can easily slot into any Blue deck, but being an enchantment makes it particularly juicy in Enchantress decks like Zur the Enchanter and Tuvasa the Sunlit, and in Blind Seer decks which run cards like Glamerdye so you can change Insight to trigger off whatever the most popular color is that your opponents are running
Beseech the Mirror already has Legacy and Vintage players brewing up ridiculous combos that kill on turn one with this card
Rampage was the first mechanic that buffed your creature in combat based on choices made by your opponent with their blockers
Shipping is one and done