It is not only traders who monitor the market and monitoring the market doesn't make you a trader unless such investor is regularly cheeking on the market to see when there is an increase so they can sell out, there are investor who monitor the market to accumulate aggressively or accumulate more Bitcoin when there is a dip and still continue with their DCA strategy so will say you are wrong by saying that monitoring the market is for traders.
True, investors also monitor the market, but in my own view there is still a thin line between how a trader and a long term investor do it. Traders usually check the market because every small move matters to their positions which is not reliable, while most long term investors do not need to sit on the screen often since their focus is more on long term than hours or days. I would even say too much monitoring as an investor can become dangerous, because you might start acting on emotions and end up getting short term mentality, maybe considering taking profit or selling when you did not plan to....
You remind me of where I came from in my Bitcoin journey, when I was constantly glued to the charts, watching and hoping that the price pumps so that I can evaluate how much profits have been added to my investment. Sincerely, it was a real pain and a terrible thing to do for a long term investor and it compounds the temptation to sell unplanned. Why stress yourself monitoring the market when you are investing in Bitcoin to hold for a long term have no business looking at the chart always and even those that want to buy more will be better of following the DCA method that is not price dependent. This will take away the stress of looking for the perfect bottom to buy which often lead to mistakes.
I can relate to what you are saying, a lot of us passed through that stage of watching charts every day and thinking that is the way to grow as an investor. At the end it only brings more pressure and like you said, it pushes one to sell when there was never any plan to sell.
The real growth comes when you stop chasing the perfect entry and just keep stacking, whether through DCA or seizing the dips when they come. Bitcoin was never meant for people to be glued to charts 24/7, it is for long term conviction. Once you understand that, the noise of daily moves becomes meaningless.