It can be a bit overkill for your use case if you only need to stream the USB media on your tv, but take a look at Jellyfin, it's a program you can install on any PC and as long as this is up and running on the same network you can access your media on that PC (in your case with the USB plugged in) from any other device (TV, other PCs, Tablets, smartphones)

Like kylian said: Kodi. You can install it even on an android device (like a firestick) or you can go for some distro giving an out of the box good experience like LibreELEC.

a small PC with kodi can do this. It can do much more as well.

There are a lot of tiny PCs these days that can output 4k video and audio. Look for something with an N100 or N200 CPU if you want to go as cheap as possible, they tend to be super-cheap and perform well. I've got one of the GMTecs and this wireless keyboard+mouse, works really well from the couch.

There are cheaper/other options but to get you started: https://www.amazon.com/GMKtec-Windows-Computer-Business-G3-dp-B0CQ4XQ2WG/dp/B0CQ4XQ2WG https://morefine.com/collections/pc-box (specifically the M9)

My solution is a bit old school: A raspberry pi connected to my network and running miniDLNA. It has an externally powered USB hard drive. My TV runs Android and I have VLC installed. Any DLNA client works including Xbox and mobile phone apps too.

I don't think mini DLNA is even updated anymore so eventually my solution might stop working but it's been running solid for 10 years

How about an Orange Pi running Android with a external USB drive?

Take a look at simple Android TV boxes with a USB port. There are plenty of options and you can just install vlc on them

Most TVs these days have a USB port for exactly this purpose, you can load media files up onto a flash drive and plug it in, then you should be able to browse the files and play it from there.

However, if you want to be able to play files hosted on your PC without having to copy them to a drive, you would have to set up a media server like Jellyfin on your PC and either buy or build a compatibility for your TV. Fire TV sticks or a Chromecast would work as cheap options to buy, or you could look into hosting a Kodi instance if you have spare hardware lying around.

There are really a ton of options, my above suggestions are only scratching the surface.

Kodi on any device should work

My Roku tv has an app that streams from network shares and my Synology NAS.

I've been using a Zidoo Z9X for streaming local media. Not cheap, but very powerful and has a huge amount of features. It'll play just about anything you throw at it, all locally.

https://www.zidoo.tv/Product/index/model/Z9X/target/VEMg6VRC2%2B9KKmVViAFMcQ%3D%3D.html

Now you make me feel old. In "the olden days" before streaming of media over the internet was as commonplace as it was now, that was the standard way that tech-savy people consumed media: Either on their PC or with some set-top box with built-in storage. I fondly remember my PopcornHour, which was basically a line of desktop-boxes that ranged from "basically a hard disk, video decoder and HDMI out" all the way to "can automatically rip your BlueRays".