You can run your own sentry server (or at least last time I worked with it you could). But as others have noted sentry is not going to provide the same functionality as OTel.
The word "can" is doing a lot of work in your comment, based on the now horrific number of moving parts[1] and I think David has even said the self-hosting story isn't a priority for them. Also, don't overlook the license, if your shop is sensitive to non-FOSS licensing terms
