anybody who stopped trading during the past 2 years and wants to start again this year must not do it and should stay away from trading. because someone who can not make profit from all market conditions is not a trader, they are gamblers who rely on constant pumps to make profit and since that is not possible they should not risk their money or they will end up losing their money again and again until they are broke.
Although I see reasoning in what you have just said but I want to look at it from this angle, every traders knows when it's profitable for him/her to trade. The smart and more experience ones can trade in any condition and still come out profitable. For those those who aren't yet that experience, they have the right to take a break when they observe the market isn't favouring them then maybe engaging in demo practice to perfect or develop new trading strategy.
What favours Mr A might not favour Mr B, but as far as both traders are putting in their very best, analyzing and studying the market to make prediction of price movement and not mere gambling on speculation of others than choosing a time that best suit them to trade isn't that bad.
Concerning the OP assumption, hope you do understand that January had various positive news like Ethereum software upgrade spreading round the community and 2020 in general is assumed to be a very positive year for bitcoin due to the hype of halving block reward and other benefits that follows like price increase, supply decreased etc so the price increase in January is just a mere reaction probably caused by FOMO as enthusiast are buying coins in preparation for the hype to kick in.