"Can companies advertise their product VHS or NTSC if they didn't quite meet those standards, etc."

All television standards are incredibly strict (once I worked in a prototype laboratory at RCA, there we designed professional television equipment, later I worked in a TV station with the responsibility for ensuring that TV standards were maintained to comply with government regulations/broadcast specifications - i.e.: in keeping with the standards).

It's somewhat of a miracle that cheap domestic VCRs work at all. The only reason they do is that it is easier for TV set manufacturers to build flywheel syncs that allow horizontal and vertical oscillators to be pulled to frequency than it is (as it was back then) to phase lock them to known precise frequencies (say for PAL: 50 and 15,625Hz). TV stations always broadcast extremely stable frequencies but even so getting a domestic TV to sync with them could be difficult. By the 1980s TV station standards were even tighter as by then they were locked to atomic standards (this made network syncing much easier).

Mechanical VCRs had inordinate difficulty in maintaining good TV standards, that is their horizontal and vertical sync blocks looked like something the cat dragged in. It's only the excellent sense of early designers who designed the television standards - and that's all of them, NTSC, SECAM and PAL - that they included equalizing pulses in the synchronizing signals. These equalizing pulses were integrated by TV circuitry, mainly resistors and capacitors, to produce pulses that were easy to lock on to. If it were not for this cleaver farsighted thinking then cheap domestic VCRs would not have been possible.

There's an excellent drawing of a vertical field block at the very bottom of this link: https://www.brainkart.com/article/Vertical-Sync-Details_1202...

It shows how the equalization pulses, which are transmitted by TV stations (as required by the standards) allow TV sets to generate pulses that are easy for TV set oscillators to lock onto and thus sync with incoming TV images. A VCR records a TV signal complete with its sync pulses and upon playback the by now very 'dirty' sync pulses that also vary in frequency due to mechanical playback drift can still be separated by the TV set's sync separator and fed to the line and vertical oscillators which then lock onto the signal. That these pulses vary from the clean ones broadcast by the TV doesn't matter much as the system was designed to be sufficiently robust to cope with bad incoming signals (even though VCRs weren't on the minds of the standards people at the time standards were set).

Essentially, domestic VCRs exhibit quite remarkable technology and its only through the dogged persistence of Japanese TV manufacturers in the early 1970s and '80s that we got VCRs at all.

In that sense it's very hard to criticize VCR and TV set manufactures when the standards were built with only electrons in mind! That is, TV standards designers knew that electrons could respond very quickly but they never envisaged that mechanical parts would also need to move hellishly quickly (the risetime of a domestic TV signal about 90ns and TV sync pulses are measured in microseconds).