Anyone know can a USB-C hub with HDMI run dual 4K monitors on a MacBook and what specs do I need?

Short version first. On a Anker 85W base M2 MacBook Air or 13 inch Pro, macOS only exposes one external display over USB‑C Alt Mode and it does not do MST for dual displays, so a simple USB‑C hub will always give you one 4K60 and the second stuck at 30 or mirrored. To run two independent 4K60 screens from a single port you either need a Thunderbolt dock or a DisplayLink style dock that uses software. Under your budget and plug and play without drivers is not realistic on that Mac.

Think of the that model-C hub as a splitter for one DisplayPort feed. Your Mac sends a single DP Alt Mode signal over the that model-C connection. Some hubs can convert that to two HDMI sockets but they are still sharing the same DP bandwidth. With DP 1.2 level signaling you have roughly enough for one 4K60 stream. The leftover becomes 4K30 or 1080p60 on the second port. Newer hubs that rely on MST to pack two 4K60 streams expect the computer to support MST for separate displays. macOS does not on external monitors. Not something macOS will magically enable with a firmware update. So for two 4K60 independent desktops from a base M2 you need a second display engine that does not come from native GPU output. That is what the that model graphics approaches provide. They present themselves as additional displays over that model and handle the HDMI conversion in the dock, which is why they need drivers. Thunderbolt without that trick will not bypass the one display limit on your model.

Yeah this is one of those Apple gotchas. The base M2 only exposes a single external display over the GPU, and macOS will not break that into two via MST. A dual HDMI that model-C hub is just combining one DisplayPort Alt Mode lane group and that model data, so you end up with enough bandwidth for one 4K60 and the remainder for 4K30 or a mirror. No way around that on vanilla M2.

If you want two independent 4K60 you either use a that model graphics solution like DisplayLink or step up to a different Mac that supports more than one external display. A plain Thunderbolt dock that only breaks out native video will still be limited to one screen on base M2. Not a bandwidth fix you can buy in hub form.

I fought this last year on an M2 Air. I tried three different dual HDMI hubs that claimed dual 4K60 and every one topped out at one 4K60 plus a second at 30. Swapping one monitor to DisplayPort did not help because macOS will not do multi stream for two separate desktops.

What finally worked was using one native 4K60 over that model-C video for my main monitor and adding a second 4K60 through a software driven adapter. That needed a driver install and one reboot then it was stable. Downsides for me were occasional HDCP weirdness in streaming sites and a little extra CPU during heavy video playback, otherwise it felt normal for office work.

On the base model without extra software, a solid compromise is one 4K at 60 and a second at 1440p 60, which scales cleanly and feels much smoother than 4K at 30; if available, 50 Hz can also feel better than 30. For two true 4K at 60, either add software help or move to a higher tier system with native multi display support and a simple adapter.