Absolutely, when you are at all but dissertation (ABD) stage you will be very deep in reading, writing and rewriting - it can be difficult to consider your research career post PhD from that perspective.
Setting aside a limited amount of time planning for a postdoc will help you consider the next stage of your research career, it gives you a broader appreciation and informs you regarding the elements of the PhD that you found most interesting and would like to pursue a research career in (as opposed to the incentive of being awarded the PhD). I would recommend the following text to all my PhD students https://theprofessorisin.com/buy-the-book/ and have learned a great deal from it myself.
Also from a practical perspective, the process of CV prepping, formulating a research statement and finding a suitable postdoc can take 6-12 months if you want to align it with your interests. Assuming your PhD is funded, if you are looking for a postdoc post-PhD without any incomre it may force your hand in both applying for positions that do not align and taking the first position on offer.