Pirate Captain Angel and the changling Vadic are both examples of great villians or foils that gave our heroes a run for their money but were not a noticeable threat to most of the Federation. Let's have recurring villians like this.
One of the things I really like about Captain Angel is that even though they're an antagonist who has done some awful things, they're not per se a malevolent person. They honestly seemed to care about helping Spock see that he doesn't have to make a binary choice between a Vulcan identity and a Human identity, they and their crew didn't actually kill or permanently injure anybody, and their goal was merely to liberate their lover Sybok from a Vulcan system of incarceration that is of questionable moral legitimacy.
(Their crew did claim they intended to sell the Enterprise crew into slavery in the Klingon Empire, but given how much less malevolent the rest of Angel's actions were, and given that Angel had a personal transport in hiding to spirit themselves away from the Serene Squall, I personally find myself wondering if perhaps Angel always intended to deliver the slavers in her crew into Starfleet custody before escaping.)
The Emerald Chain was great. Let's see more of that. A local villian threatening a stellar neighborhood or some small corner of the sector. The Sona! Only one planet hidden inside a nebula was in trouble.
I do think smaller-scale antagonists are the way to go, yeah.