The answer depends on the type of requirement, the client's budget, the scope of the work, the future maintenance, the necessary manpower, the timeframe, the project schedules, etc. It is therefore essential to choose the website we are going to use. design, build or develop.
If you are a complete programmer and you have special tasks to do that are only possible with Joomla, then go for it.
Besides, if your need is for WordPress, then go for it.
But we should have a clear idea of the features of Joomla and WordPress. We have Magento, OpenCart, Prestashop, Shopify, WooCoomerce, etc., as many points to consider, if you have an interest.