It really depends on your needs and goals, but generally I take a practical view to presets. There is nothing inherently wrong with using presets, the right sound in the right context is all that matters.

However, if your desire is to develop a unique voice as an artist, you will probably be well served to create a lot of your own custom presets and custom sound libraries (in addition to using built-in presets that you like.) If you are beginner don't fall into the trap of acquiring an endless amount of VSTi's - focus on learning a few synths at deep level so that you can at least competently modify presets that you like to suit your needs.

I rarely use presets, honestly because I don't like many of the factory sounds. I have my own preset banks I've made, but sometimes I prefer starting from scratch anyways. Sometimes starting from a preset feels limiting or that it constrains the direction of sound design (for me, at least).

I think presets are a good choice for beginners who don't really have an ear for sound design or synth programming. They're the equivalent to me of guitar tabs. As training wheels they do their job but eventually you want to take them off as you get more familiar with sound design.

The reason why I like presets is because they can help you discover new sounds that you didn't think were possible.
The reason why I dislike presets is because they overcomplicate the amount of choices you have to choose from. (At least for me when I was a beginner)

I remember being so overwhelmed by sound design when I was first starting off because of how many presets there were to choose from in instruments like Massive or Sylenth. Once I realized that the majority of these presets were just variations of a square wave or a saw wave it simplified dance music instrumentation so much for me.

When I choose my sounds I like to browse through the ones I've already memorized in my imagination. In the same way I imagine drums or a bass in my head I do the same with commonly used synthesizer sounds. (supersaws, plucks, leads etc...) I find this method to be much faster than browsing through 100's of presets hoping that I come across the right sound.

use them to learn