Website accessibility matters if you want more people to use your site. A visitor toolbar can be a useful first step. It helps visitors. It doesn't replace fixing your site.
Many businesses start with a widget because it's quick to add. That can give people controls for text size, contrast, and reading the page aloud. It still won't fix every barrier in your site's own code.
When you compare options, look for clear limits on what automated tools can find, people who can audit and fix issues in your code, and support that stays with you as the site changes.
Start with a free one-page scan at webmax.co/audit. It helps you find issues on one page. It doesn't replace a full audit or fixing your site.