> it's also not possible to use new versions on older hardware, they started to require more minimum RAM/FLASH.
You shouldn't imply that OpenWRT is in any way bloated.
The kind of hardware that doesn't have enough RAM or storage for OpenWRT is truly pathetic. Those devices don't have enough CPU power to route traffic at reasonable speeds, their WiFi radios are so outdated that operating them in a crowded 2.4GHz band is an obscene waste of airtime, and even with the manufacturer's firmware those devices usually can't support features like IPv6. A router that old is usually only worth using as a managed Ethernet switch, if it even supports gigE.