You're missing out if you don't have such thick mass of warm brick/stone. If you only knew how great it is to sleep on top of it (my grandmother had similar to that in her house :)

https://en.wikipedia.org/wiki/Russian_stove

Modern fire codes require large space between a stove and walls which is usually goes unused where it could have been really filled with such a thick brick structure with the smoke passage snaking through it like in Russian and German stoves. Or like this:

https://www.mha-net.org/wordpress/wp-content/uploads/2020/05...

Fire codes in the UK would allow a stove as close to the wall as you would like