With the levels of QAM on decent current model HomePlug kit, speeds are pretty reasonable even on older or interference-prone wiring. The advances (including borrowing MIMO techniques for inhibiting crosstalk and increasing raw physical speeds) are certainly advantageous if you have the cash to buy higher-end units. I certainly have no hesitation in recommending powerline ethernet solutions instead of WiFi. I usually have a couple of basic plugs knocking about for temporarily extending ethernet to somewhere. TP-Link make great units if you don't fancy paying double for Devolo.
That said, Devolo, Zyxel, Actiontec, Comtrend and others also make G.Hn Wave-2 compatible units which have greatly increased speeds, up to 1 gigabit/sec real world achievable on the fastest units. I think that's pretty impressive.
Radio hams loathe powerline adapters, and I can understand why... The current frequency bands some of the units can work at are now breaking into the FM band
As WiFi standards are developed, the frequencies increase and thus some of the advantages of higher throughput and channel congestion management are outweighed by increased propagation loss characteristics and unpredictable range. Even with 4x4 MIMO speeds can be disappointingly low. I can't get as fast as some AV600 homeplugs to my ISP's WiFi router when I'm LOS about 15 feet away.
I think you need to have pre-1950s wiring to really be better off with WiFi. Powerline will not give you record-setting headline speeds in
most cases, unless you splash the cash, but their speeds will be more consistent and more stable latency (and packet loss-wise) than WiFi. Add to that the improved physical security, transceiver unit encryption, and it's arguably more secure than broadcasting your bits OTA. PLC isn't perfect (e.g.
this 2019 Synacktiv presentation) but for your average home setup, it's as safe as WiFi. Only running Cat5/6 everywhere is going to be better.
And if you fancy a laugh, check out
https://en.geovital.com/ethernet-over-power-line-eop-powerline-powerlan-and-health-effects/