I'd make a point that if you're planning on playing a tank, you'll likely have to upgrade sooner, most likely at around 75 in Shadowbringers (Previously it was at 55-57 in HW before the Aery or Vault depending on quality of gear, and 65 in SB before Bardam's Mettle).
This is because stat wise the high level tome gear is fine, but it has a really bad armor value compared to gear at a similar level.
While it wasn't great, if you didn't go crazy on the pulls, used cooldowns, stayed in tank stance(which there's 0 reason not to anymore in 5.0) and had a semi competent healer, you could kinda do the same as everyone else and just upgrade whatever dropped.
If you play tank as first char through the MSQ though, you'll be given white HQ gear as quest rewards anyway, so you just equip that(and not be a cheap fuck trying to sell it for a profit). If you play it as a second char, the amount of dungeon runs you do should be no issue with the guaranteed drops to replace most of the scaevan stuff by the time it starts sucking anyway.
Overall, you don't really have to go out of your way to upgrade your gear other than choosing purposefully not to equip the gear you're given in the MSQ which sounds retarded. Don't even have to use all the HQ gear, you can skip the first 2 tiers and get the 75 stuff.
Bardam was pretty bad during SB launch more because of other issues. Lots of tanks who thought they were pro shit running str accessories and having less hp than everyone else as a result(like literally, retard tanks with 21k hp running str accs with crit materias and UNAUGMENTED armor when everyone else had 25k hp), not upgrading their armor with the free shit and just being shit tanks in general, either trying to pull 3 packs even though they were like 20secs from each other, without using sprint because these cunts were fucking retarded, and then not using any cooldowns until they dropped to 5% hp. Combine with Bardam trash being a fairly large step up in the damage department(motherfucking bears hit hard, even with good gear) or having annoying shit like the face tablet guys shooting beams at the healer constantly forcing you to move, which made spam healing harder. But I also had no issue healing the good tanks even with full Shire, and myself tanking some Bardam with nearly full Shire on the first couple of runs on my first tank leveling(granted it was PLD, aka I have cooldowns for when my cooldowns are down).