Reading through some more scientific reviews article, it seems like a lot of the risk comes from animal-based product consumption particularly. For instance, one study found increased all-cause mortality for keto with higher animal product consumption and decreased levels for a plant-based keto diet. However, given that most studies aren’t focusing on that, it’s still hard to tell if there’s other risks not being included there. Additionally, a lot of the touted benefits of keto appear to wane over time and don’t end up doing all that much better than other diets

I’d still recommend just being careful about it

Longer-term effects [of Ketogenic diets] can include decreased bone mineral density, nephrolithiasis, cardiomyopathy, anemia, and neuropathy of the optic nerve (82, 121). Ketogenic diets have low long-term tolerability, and are not sustainable for many individuals (48, 49). Diets low in carbohydrate have also been associated with an increased risk of all-cause mortality (122), although recent data suggest that lower-carbohydrate diets can be linked to either higher or lower mortality risk, depending on the quality of the carbohydrate they contain and whether they rely more on animal protein and saturated fat or plant protein and unsaturated fat, respectively (123).

https://www.frontiersin.org/articles/10.3389/fnut.2021.702802/full#h1

Unfortunately, these effects seem to be limited in time.

https://www.mdpi.com/2072-6643/9/5/517?d=40&cgid=9aS3