For pipelines, studio pipelines extend to far more than just the file format as I/O. It's things like integration of asset management tooling, referencing setups and the ability to send data easily between applications and departments.
Blender has alembic support which is great for geometry, but its USD support is still nascent and limited to export. Additionally because it doesn't use Qt, it's hard to integrate tooling that can otherwise be shared between apps. (note there are third party projects to integrate Qt in Blender).
It's also only recently that Blender has started following the VFX reference platform, which previously meant that all your dependencies and Python code needed to be redone to support Blenders versions.
The support for things like OCIO etc is also relatively new.
With regards to the Blender foundation and support contracts, it's quite different than what a traditional support contract offers.
Usually a support contract means you have a dev that responds to your companies needs, where they'll support you with custom builds of the software if needed, including back porting patches to your production locked version.
The Blender foundation instead takes donations towards development of future versions of Blender and it's still very hard to convince them to support specific studio needs. You're most likely NOT going to get backports of fixes to a production locked version of Blender.
It's only recently (2.83) that they've started having LTS releases..
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To caveat all of this, I'm not saying Blender shouldn't be used for productions. It's very capable. I'm just providing perspective on why it's not finding a strong foothold against incumbents even when it has some very strong on the surface features that Maya doesn't for example at an infinitely better price.
I have confidence that the Blender foundation are moving in the right direction after what seems to be a cultural and priorities change with 2.80 onwards.
Part of the 2.80 changes also brought a lot of outside funding from Epic, Ubisoft, Facebook and more that I believe will help steer Blender well in the future to unseating Maya etc.
I don't see Blender unseating Houdini anytime soon though.