I think if you have the ability and time it is helpful to learn your own taxes, to the extent they aren't too complicated. By understanding them it helps you plan better. I could have saved money in the past when self employed by paying myself a lower salary and dodging some payroll taxes, or perhaps paying my kid to empty my office waste baskets, but I decided that the marginal savings wouldn't be worth the time and complicated, and would have mostly been offset by fees paid to the cpa. If I had a full fledged business I would absolutely hire a cpa but I'd understand every damn line on the return.
But at least a good cpa is worthwhile in some applications. I honestly believe there are very few good financial advisors, because the way the are compensated is not in alignment with the clients interest. And people think it is very complicated but it doesn't have to be. You can literally put it on one low fee index based target date fund and be better off than what you get with most advisors, which will likely consist of high fee / load funds and a whole array of different individual stocks, which is really a completely pointless approach other than maximizing broker commissions.