SQLite will ignore most type information, instead choosing to focus on "type affinity": https://www.sqlite.org/datatype3.html
I would look into Berkeley DB (BDB) which is one of the most widely-used embedded databases, albeit not a SQL-based one. Otherwise take a look at the list of embedded databases on Wikipedia: https://en.wikipedia.org/wiki/Embedded_database
I'm not sure of the rationale; perhaps it's easier to keep the code / database files portable amongst different systems this way, and since it was designed for embedded use, many systems (and thus incompatibilites) were envisioned?