This only holds if you assume telemetry means personal data, but that is a very big if. Meta, Google and other giants generally deal in telemetry that includes personal data, however for most run of the mill software that's not the case. Outside of advertising, I would argue that for most applications you're already pretty close to being clear of personal data as long as you exclude the user's email and other identifiers from the logs. Sure, there are examples where this is not the case, but it isn't even remotely as big of a problem as you claim it to be.
A lot of telemetry can become personal data. Filenames etc. are the easy parts.
Telemetry needs to be motivated for it to not be considered spyware. You need to really consider what you are logging and why, and then, is it worth the downsides.
It is not something to take lightly, hardly "no harm".