Interesting topic, seems like there could be quite a few factors separating the two. E.g passion of a collector vs consumerism of an accumulator. Seems to me an enthusiast would more likely describe a collector. I think this topic needs a thread.
I just think “accumulator” is used negatively almost always, so I think there needs to be a distinction between someone who has a focus and intent about their buying (a collector) vs. someone who is passionate about something but who just buys what they like without it having any specific direction.
At its most basic, any enthusiast has a knife collection, but I think that’s way too generic to be useful here.
I am a watch enthusiast as well. Very interested in them but I have no specific direction to what I buy, aside from liking it.