none of these companies offer monthly subscriptions - they offer a 12-month subscription billed monthly or annually (with a slight discount), your choice.
This is adobe's whole schtick with the cancellation fees for example. You pay 50% of your remaining subscription balance as a termination fee. So if you subscribe 3 times a year for a month and then immediately cancel you are paying more than a yearly subscription.
Even a 1 month subscription for 2 hours of need is too much though. Thrice a year, for a few hours each... But have to pay 3 full months usage is nuts. 12+ months is even crazier.
Bill per hour would be OK.
Or buy once, give me 1 year of free updates but I can use it as-is forever (like intellij) is also fair.
This is adobe's whole schtick with the cancellation fees for example. You pay 50% of your remaining subscription balance as a termination fee. So if you subscribe 3 times a year for a month and then immediately cancel you are paying more than a yearly subscription.