Modem and Router for 500 Mbps Plan

Looking for a reliable router and modem that will take full advantage of a 500 Mbps plan.

Need to support up to 2 people who work from home, streaming, and online gaming (PS5) within 700 sq ft. If a 500 Mbps plan is overkill for this, let me know.

Current setup is a DOCSIS 3.1 modem and the TP-Link Archer A20 router. Over the past month and a half ive been experiencing a lot of packet loss and latency issues while playing online (connected via ethernet) and working from home (Wireless). While there are currently 3 people in the same place for now, I haven't had any problems for over a year until recently. I've also had technicians come out twice and they said everything was fine. Does this set up already take full advantage of a 500 mbps plan or do I need to upgrade equipment? Should I wait to see how things go minus one user?

Side question - does every router only have LAN ports that output only up to 1 Gigabit or am I reading these descriptions wrong?

Thanks for any advice.

Edit: I'd like to keep my budget at around $300 for both modem and router if possible.