Ting does Verizon network service now in addition to T-Mobile, and they have both prepaid-style bundle plans and postpaid-ish pay for what you use type buckets. $10/month for "unlimited" talk and text per handset, plus $5/GB shared across devices, plus taxes and fees with postpaid billing is probably the closest you'll get to Fi-style a-la-carte pricing.
However, it's worth noting that Fi-style pricing is a bit more expensive than some of the Verizon MVNO plans you can find with outfits like RedPocket and US Mobile. To illustrate the price difference, $40/month between Ting and RedPocket for two lines, RedPocket provides 3GB of data per line, and Ting provides 4GB of data shared. US Mobile is a lot lower than even RedPocket, given they offer an "unlimited" talk and text plan for $12 with 1GB of data plus tax and fees, and $15 for 5GB of data per line, and they also now have pooled data plans for sharing between lines, at $9/line plus $2 per 1GB and taxes and fees, which puts them at a break even with Ting's prices for two lines and 3GB of data for around $25, with US Mobile being cheaper as data usage scales up. But that requires you buying in bulk and being okay with leaving unused on the table.
Ting's owned by Dish Network now (no longer Tucows), and their website's apparently become a bit dated/inaccurate with some more nitty gritty info, but others here still seem to be happy from what they say for what it's worth.
US Mobile has the cheapest prices of the lot for prepaid pre-bundled plans. I used to be on US Mobile in the past before switching to RedPocket, and they were fine at the time... but I don't know anyone currently on US Mobile, and I've heard that their support quality has begun to reflect their dropping prices, but that's third hand scuttlebutt. They also offload a lot higher service fees into the fine print. Do your own research and read the terms of service with anyone you go with. This said, the axiom of getting what you pay for holds just as true in the MVNO space, and sometimes it's wise to not choose the absolute cheapest... but that doesn't mean you still can't be overcharged.
It's also worth noting that Ting and Red Pocket are on
Apple's official approved provider list, so
most of the core iPhone exclusive, data-dependent features should work as expected... which is more than can be said of your experience with Google Fi. As Visible has been mentioned, it too is on that approved list... however, US Mobile is technically not, even if they'll activate iPhones and most iPhone features usually work without much fuss on a Verizon MVNO, and hasn't been near the boondoggle that iPhones on unapproved AT&T MVNOs have historically been.