Sometimes a static zap could destroy $10K's of sensors/systems/labor. Lots of the things I make are very expensive one-off products or sensitive electro-optical systems. They aren't expensive (well, some may argue that they are - they are $50-100 IIRC in a good size, but mine is over 5 years old, so even at the high end, I'd say it's worth the <$20/yr) and are great to work with. I'll CA or epoxy anything I want and if I spill or cut the mat doing something it doesn't matter at all. I'll often wipe down the mat (rather large, at least 4-5' across) with isopropanol and tape PCBs or other object to the surface for fine solder work or component placements. I often will strip large gauge wire, or very small gauge wire by rolling it across the surface and lightly scoring the insulation with an xacto until it is ready to pull the insulation back.
The ESD mat has some compliance or give to it mechanically. I've used maple tops before FWIW, but my current home-lab has a formica wrap-around surface installed (super awesome BTW).
