Mplus is not sold on a subscription (thankfully), but the perpetual license model has quirks.
to multilevel and longitudinal modeling within a single framework Mplus Home Page Intuitive Syntax mplus reviews
"We test item-level DIF (Differential Item Functioning) across 12 countries. Mplus handles multigroup CFA and alignment optimization effortlessly. For psychometricians, there is no debate: Mplus is the tool." – Senior Psychometrician, Testing Org Mplus is not sold on a subscription (thankfully),
For a lab or university, site licenses run into the thousands. site licenses run into the thousands.