Absolutely true. One of the things I learned decades ago as a solo entrepreneur was to force for as much commonality as possible across everything I was doing.
When you wear many hats you have to mentally task switch between domains and this time can sometimes be measures in weeks (example: you've been doing mechanical design and you now have to switch to FPGA design after months of not touching the codebase).
This is why jumping on the latest and greatest trends isn't always the best idea. Languages, tools, frameworks, new chips, new FPGA or CPU architectures, etc. Things that don't mesh at a certain level impose a cognitive load that can really slow you down.
The simplest example of this I have from years back would be using C and Verilog on embedded systems. While Verilog is not software, it's hardware the "C" feel to the language --as opposed to VHDL-- makes for an much easier transition between hardware and software development, at least for me.