In SPARQL you can write queries that involve any graph relationships that come into your head. You can take the UNION of multiple graph patterns. With SPARQL you can also get back 200,000 or more results.
With MQL you quickly run into the wall when you find that you can't write the query you want (you need to write 10,000 queries instead of one) or that the query you want to run times out, or that it only lets you get back a limited number of answers.
It's also possible to do batch processing with :BaseKB Pro with extreme efficiency. We did a calculation that would have taken 100 years on the biggest machine in the AMZN cloud in SPARQL in just 24 hours on a mac book pro with an optimized pipeline.