What are alternatives to linked servers for integrating data from multiple different database systems, and when might they be a better choice?

Alternatives include using SQL Server Integration Services to build scheduled extract, transform, and load processes that copy data between systems on a regular basis, using PolyBase for querying large external data sources more efficiently, or building a dedicated data warehouse that consolidates data from multiple sources, all of which can offer better performance and reliability than querying live across a linked server for large or frequent data needs.

-- Instead of querying live across a linked server every time,
-- schedule a nightly SSIS job to copy relevant data locally
-- for faster, more reliable reporting