Unfortunately, your personal experience doesn't change the fact that Google do classify significant amounts of legitimate mail as spam. It appears that at some point in the somewhat recent past, they may have decided that literally anything new sent from a domain without SPF set up is spam, for example. That is simply broken, but they appear to have excessive spam filtering in other respects as well. We even see things like payment confirmation emails, which we are legally required to send and our customers might actually need, and which are basically factual plain text and a very lightly styled HTML version, getting rejected at times.

Personally, I'd rather a few false negatives hit my inbox and click the junk icon for a moment to deal with them than actually important things get lost in junk and opportunities missed as a result. I honestly have lost count of how many times I've seen that happen recently, but it's a lot, and it's almost invariably been a result of excessive spam controls by Google and one or two other big mail services.

Several of these I specifically have incoming mail filters for, and they still go to spam at random.