Over the last 20 years or so the small engine lawn tool market has gone through big changes. One of the biggest changes is that small engines had to be redesigned to meet air quality standards and emission laws…just like your car. Probably more important, many had to be redesigned to perform using gasoline that includes ethanol.
In addition, there was widespread marketing to introduce many of these tools to the general public. Historically, only individuals specifically trained owned these types of tools. And while many new owners were happy to learn the proper way to care for and maintain their new purchases, others were happy to just get them started, get the job done, and put them away until next time. Even if next time, was next year!
If you don’t care for and maintain your gasoline powered tools properly, they are unlikely to work when you need them.