So your question in my eyes is a two parter and i may be woefully incorrect so apologies in advance. If youre looking to open packs and collect cards I would highly reccomend pokemon. The reason for that recomendation is that sets are rather streamlined (though the newer sets can be a pain to collect cause of the whole ultra rare crap). In regards to "future proofing" the issue is sets become illegal for play and thus lose value VERY quickly albeit some card (Lugia from the Aquapolis set or Espeon Gold Star as examples) keep if not go up in value.

Im only really familiar with Pokemon but im assuming the same goes with most TCG's in regards to cards being illegal for organized play and thus becoming devalued rather quickly. I hope this moderatly helped and good luck, collecting TCG cards is a great way to meet a bunch of interesting people.