For example, Wifi 7 doesn't make actually useful MLO mandatory. So most wifi router manufacturers - even Ubiquiti - don't implement it! What's the point of adding something to the standard if it's optional.
Ideally, the standards body should make expensive stuff mandatory- then prices will come down as soon as everyone is building it, due to economics of scale.
Cost certainly is the primary factor in the decision, but you definitely want those low-bandwidth but long-range devices OFF your precious 5GHz band.
Unless you want the same crappy experience of 2.4GHz band in 5GHz.
If you have a mesh system with more than one access point, your network benefits greatly by using WiFi 7 (or 8, now) as a dedicated wireless backhaul that connects the access points to each other.