WiFi networks are built up of a number of channels through which communication takes place. The bandwidth of these channels is 20Mhz both for 2.4 as well as 5Ghz. The bandwidth determines max comms speed, so in essense this is the same between 2.4 and 5Ghz. However, the 2.4Ghz frequencies are unregulated so you’ll find just about anything using these frequencies including your microwave (which is noise of course). The 5Ghz is regulated and therefore signals have better SNR i.e possible effective throughput.
Higher frequencies are easier attenuated by building structures etc. Additionally, there are differences between the 2.4G and 5G radio power affecting total distance.
So if you have a good quality signal (throughput) on 2.4G i would stick with that, it is just less finicky to make work consistently. Then again, if you’ve got an eero system you don’t care, it just works
PS: Some routers can bond wifi channels which add bandwidth and thereby throughput. But if there is broadband noise sources, the wider bandwidth might effectively work against you. Many can adjust radio output power giving better range and SNR. All this affects how well 2.4 vs 5G works in your specific set up…