I asked the same question. Nothing particularly bad, but doing it for a single security sounds stupidly risky, particularly one with this much hype. SQQQ is probably a better play if you expect tech in general to crash back down again.
I did the capstone dungeon at level 62. I've seen people do it at 61 solo.
However, the lowest level mobs in Tier 4 are level 73, and they hit twice as hard, so you're not going to jump straight into tier 4 until 65 or 66.
I think this is intended. 50 is basically the pre-endgame.
They did a good job making it feel like the "real game" starts at 50 instead of starting at 100.
RE: Seasons.
There's so much stuff you have to grind to even begin to build a character in this game, I don't see how people are going to want to consistently regrind new characters every season.
FYI: I beat the level 70 capstone dungeon at level 62, go into T4 and the lowest level zones are level 73 and everything just eats me.
That was not worth it.
PS: More item porn from my character:
I'm not going to buy this because I guarantee within a year it'll be in a Humble Bundle monthly bundle. Possibly on Game Pass.
Every 40 dollar game ends up being like that.