[fsh]

With smaller reactors, one needs more of everything: reactor vessels, containment structures, cooling systems, generators, etc. This is why industrial facilities are usually built as large as reasonably possible, and why SMRs fell out of fashion as soon as GW-class reactors became feasible in the 1960s.

[p2detar]

SMRs have their use. Depending on the model and design you can build them or even bring them [0] to a remote place where you want to build industry but the infrastructure and access to electrical grid is lacking. I'd argue nowadays they are even more important with the huge rise in electricity demand.

0 - https://en.wikipedia.org/wiki/Akademik_Lomonosov