There are exceptions where the answer flips immediately. If you sell a physical product, product photography is not decoration, it is the product page, and poor images suppress conversion measurably regardless of everything else. If you are in a category where the aesthetic is the offer, such as interiors, food, events, or anything visual, the photography is the demonstration of competence. And one decent photograph of you is worth commissioning even when nothing else is, because people hire people and a poorly lit selfie undermines a page that otherwise reads well.
What you can do yourself is more than most owners assume, and the constraint is light rather than equipment. Photographs taken near a large window on an overcast day, with the subject facing the light, will beat anything taken under office lighting with a better camera. Shoot far more frames than you need, keep the background plain, and hold the phone still. Editing beyond straightening and mild adjustment usually makes small business photography look worse rather than better.
Where you will feel the limitation is consistency. A set of images taken over months, in different light, at different times, will not sit together on a page, and that unevenness reads as amateur even when each individual image is fine. That is the real argument for a professional shoot: not any single photograph, but a coherent set produced in one session that looks like it belongs to one business.
If you do commission somebody, be specific about what you need rather than booking a session and hoping. A list of shots tied to where they will be used, the orientation each needs, and the aspect ratios required for your site and your listings will produce something usable. Photographers deliver what they were briefed to deliver, and a vague brief produces beautiful images that do not fit the spaces you have.
And establish the usage terms before the shoot rather than after. Who owns the images, what you may use them for, whether that includes advertising, and whether the licence expires. Photography is one of the areas where businesses discover years later that they do not have the rights they assumed, usually at the moment they want to use an image in a way the original agreement did not cover.