I've heard these "strikes" referred to as "head slaps". The term, "thermal asperity", is used to denote the temporary heating that occurs in a read head when this happens. ISTM that the lubricant coating on the platter surface mitigates the possibility of permanent damage. In fact hard drives perform "patrol seeks" so that the lubricant doesn't accumulate under a stationary head.
As for "head crashes", high RPM enterprise drives working in environmentally controlled servers frequently sustain media damage. In fact that seems to be the most common failure mode, if HDD Guru is any guide. As for the headstack slamming into its limits, ISTM this could only occur if the drive loses servo control, which in turn would most likely be the consequence of media damage or a head fault. Of course a head fault could be the result of too many head slaps, with each slap partially degrading the read element until eventually it no longer reads at all.
That said, older drives parked their heads on the platters in a laser roughened landing zone, so I'm left wondering why this doesn't constitute a crash. In fact modern drives park their heads off the platters on a loading ramp.
See the following blog article. The contaminated drive didn't crash, but it did develop bad sectors.
Opening the hard drive – Regular vs. Clean room environment:
https://hddsurgery.com/blog/opening-the-hard-drive–regular-vs-clean-room-environmentSome 35 - 40 years ago, I used to repair head crashes in Control Data BK7 drives. These had removable disc packs. After cleaning the pack area, I would disable the servo, spin up the drive and allow it to purge for an hour. I suppose the same could be done in PC HDDs, assuming that the MCU doesn't register an error condition and allows the motor to keep spinning. The air turbulence would hopefully blow the contaminants into the filter.