Isn't it a different kind of thing? Liquid fertilisers are immediately available to plants & can even be used as foliar sprays. Comfrey tea is easy & quick to make too compared to good compost.
I haven't got the space to grow comfrey but I'd highly recommend a wormery. Adding a couple of handfuls of the compost they create to a bucket of rain water, straining it & using to water promotes the soil bacteria as well as adding nutrients

Really it depends on whether you want a liquid feed or good compost...circumstances alter cases.

if you want liquid feed then comfrey is excellent. It is readily absorbed by plants as a foliar feed or by root uptake. if you only want to compost it then it adds its nutrients to that. but both are valuable methods of making nutrients available to plants.

Thanks folk, I think I’ll stick to the comfrey tea I’ve always made.