task210 OpenWRT looks great! Instead of sourcing a mini PC to for OPNsense, I just buy a router and flash it.
Networking is already technically hard, and when you include cost considerations it's really difficult to chose.
In terms of hardware, keep in mind that you get what you pay for. So if you want to have a VPN set up right in the router, for example, you won't achieve great speeds with most wifi routers out there (Glinet has a table on their sites for VPN speeds if you want to compare models).
Also, some routers don't even have enough space/processing power to host AdGuardHome/pihole locally.
For VLANs most routers don't have a switch, so adding a switch might be still another cost.
Truthfully? It's hard to decide.
For just replacing an ISP router, a wifi router with openwrt is definitely the best option.
But as we go down the rabbit hole, I'm not sure a Protecli with opnsense is such a bad idea, even though it might seem more expensive at first.