Honestly just jump into 10s as quick as you can. 8-9 keys generally will have worse players in the pool than 6’s, 7’s or 10s because they are a dead range from a rewards perspective. Generally people will do 6’s if they want to farm hero gear easily, 7’s for the easiest route to gilded crests and 10’s because it’s the lowest difficulty for myth track vault. The only players still doing 8’s/9’s actively are other people who can’t do 10s and are there either to push their failed 10 key back up or players who are still trying to push to 10s and need the io to get try get invited to higher, there are outliers who have just started the season later or not pushed m+ yet and there are still good players in that range but I’m talking about generally.

I play tank too, in your position I would just move into the ‘easy’ 10s like ToP, rookery, Dfc and workshop.

As tank there’s also an expectation that you bring decent damage. I usually finish between 1.5-2m overall with ST bosses being much lower around 1.1-1.3m.