Trading and timing works together because if you don't time the market to enter at the exact time you are suppose to enter, you'll miss out of getting the full profits of that trade that you entered and sometimes you get to lose because you entered wrongly. This is the reason experience is very important for any individual that wants to become a professional trader, you need to know when to enter the market and when to exit the market or you lose always.
Of course, trade and time are inextricably linked. As you said, if you want to trade but you don't have the free time to start then it will be a waste. I think it's quite common for some traders to lose time or maybe miss the moment that they should take and I think it's a common thing that often happens and it's not uncommon for those who experience it. It happens usually because of their inadvertence because maybe they have other activities out there, and also in my opinion if at that time they take the opportunity to open their trade it cannot be ensured that they will be able to make a profit, the market is very volatile and they can suddenly experience a loss there. You need to train yourself by learning various knowledge from other professional traders or you can also learn from the mistakes you have made, and if you already understand each time movement in a certain time range then I think you will have no difficulty in finding the right time to open a trade.
Exiting a trade is as important as entering a trade, most traders are good at one but bad at the other and exiting a trade is where most individual traders aren't very good at and that's why we have many traders losing more than winning because of bad timing of the market.
And yes, this is usually their problem especially for beginners, they have the knowledge of when to enter the market but on the other hand there are also those who do not know when to get out of there. Many of the traders are then trapped because maybe they have made a profit that makes them feel happy and after that they forget to get out of there and forget some of their trading plans. The market will not always be in our favor, and with that it is very important to implement various trading plans such as take profit when you win and also stop lose when you lose. All of that should be applied in every trade because that's the only thing that can help them to minimize their MC.