For me, simpler is almost always better for a website, so if I can accomplish a task without another plugin, that’s my preference. However, I also consider the cost(s) in terms of time and effort of developing a custom solution versus using a plugin to accomplish the task. In this case, the work won’t end with development, either. You’d also have to stay up-to-date with changes in e-commerce SEO and structured data, modifying your theme to keep up. If you were to display your products without WooCommerce, you’d have to do a lot of custom coding for your theme just to come close.
WooCommerce makes a pretty slick product catalog. It has a lot of nice features built in, like product image carousel, tabbed description, attributes, categories, tags, data schema, etc., and with the right theme, it’s mobile-friendly even with all the bells and whistles. Plus, you’ve got the WooCommerce developers constantly working on the platform to keep it current, which removes the burden from you. Not only that, but if you think you may one day sell online, using it now would make a lot of sense, because you would already have your product catalog built.
Using a popular e-commerce platform like WooCommerce gives you another advantage that you’re already getting with WordPress: the search engines know it, and are pretty good about indexing it. If you do a lot of custom fields, you’re going to need to make sure your nomenclature is something the search engines will like to accomplish the same results, though if you’re not worried about search engine results, this may not be an issue for you.
Healthier for your website? Yes, I think going with a custom solution would be healthier, but I think you’d be working a lot harder and probably losing a lot of benefits that using WooCommerce would provide out of the box. Using WooCommerce would also make it a lot easier to maintain your site down the line with changes in e-commerce and changes in WordPress.
