edit: i am pro clean power and i believe nuclear waste can be stored safely; I just don't want to put town's at risk via under secured nuclear facilities.
All the site prep work, concrete, electrical grid connections, steam generators, water etc is in one place.
The good news from the security prospective is that SMRs will likely be similarly concentrated, just with greater numbers of reactors. They are highly unlikely to be sprinkled about willy nilly, despite the thinking of some. Siting is a major problem with all power generation and particularly with nuclear: getting a site approved is a major accomplishment involving no end of costly wheeling and dealing over many years.
Although there are use cases, often championed as killer applications for SMR, such as very remote, undeveloped locations, I expect that for every 1 such isolated reactor actually deployed, 100 will be lined up in rows and columns at major reactor sites.