23andme only searches for known snips (SNPs, single nucleotide polymorphisms), they don't scan the genome, that is still a fairly costly and slow procedure (although it's radically getting cheaper and cheaper!).
Lots of people offer whole genome sequencing. Dante Labs is currently offering it at EUR 259 (no affiliation: I got their mailshot because I bought their lower still Black Friday offer). Typical lab costs are thought to be more in the $1k range, with the assumption that some of these offers are made with the intent of rapidly acquiring a large corpus of anonymised full genome sequences which they hope most of their customers won't opt out of being analysed for commercial scientific research.
https://customercare.23andme.com/hc/en-us/articles/115004459...