You can definitely still do it. I would say it is a bit less popular now though as the pandemic slowed travel, and credit card issuers have gotten used to churning and managing breakage/risks.
Chase still offers big incentives on office supply stores, so that's probably the main driver of MS right now aside from sign-up bonuses. Staples quite frequently offers $0 fees on their gift cards to encourage this.
You definitely can. I used to say "maybe not in the sfbay area" where all of the opportunities have been mined, but, no, there are still opportunities for MS even there. Outside of sfbay the sky's the limit.
