Themes are typically made by developers looking to make a small amount money by selling them online to agencies across the globe. They need their themes to work across a whole range of industries and as such they tend to contain bloated code and features that aren’t necessary for everyone. Other issues include a lack of focus on security, performance and conversion led design.
The benefits of themes are that they are substantially cheaper than a custom made site. For a lot of SME’s where ranking on Google and conversion focused design aren’t required, themes are great. For example, websites for hairdresser’s or beauty salons don’t require a custom build, a theme will suffice in sharing their offering, opening hours and contact details.