A lot of people are betting serious money that they will cheaper, more flexible, faster to build, and safer. Including me - I'm working in the industry, and I think they might very well be future backbone of energy production.
But there's a real possibility when all this shakes out that SMR's only advantage will be their flexibility. And that might be enough. A major issue with gigawatt scale nuclear is that it's frankly too big for most markets. Only very large electric markets can can easily digest a new always-on 1000 megawatts of electricity, and you need to be building multiple plants at a time for this all to be economical. That's why the nuclear power rollout of the 60s through 80s worked, and why China and to a lesser extent India's nuclear industry is thriving presently.
With an SMRs smaller scale, there are just way more available projects where nuclear is feasible, and so a more consistent workload can keep everyone employed and subcontractor's backlogs filled. The flexibility in scaling lets you reclaim the benefits of having an experienced workforce and that knows how to build nuclear power plants, something we lost in the west when we stopped building them.
What % of global electricity production is in too small markets? Seems to be working well in EU at least, markets and grids being multinational.
I'd guess many places in Africa could be potential markets that have underdeveloped grids but growing economies and populations. Hence the SMR industry in South Africa since the 90s I guess.