Not really, it's still a 2*880 MHz mips1004Kc mt7621a SOC, yes its hardware acceleration can route 1 GBit/s wirespeed, but not while using sqm ("w/ cake") - not by far. The quoted 150 MBit/s figure is presumably within the expected ballpark for that.
SQM really bogs down the ERX because it depends on an ASIC for accelerated streams that precludes any sort of inspection. It's pretty basic, underpowered MIPS hardware otherwise.
Router OS 7.1 supports CAKE and fq_codel but their sub $100 routers can't do CAKE @ 500mbps, I think their new RB5009 can handle those speeds without problems since it's a quad core Cortex A72 but the price is $220 and no OpenWrt support as of now.
My best bet would be a RPi4 and external AP/switches as others mentioned.
Unless there are obvious problems, the RP should be quite stable. I've been running one as a backup server for many months without any quirks (touch wood).
BUT they need to be shutdown properly (not just powered off) and they need clean power - get an official RP power supply. Mine runs off a UPS, and has not yet fallen over