There is no definitive answer to the question of whether free blogger themes are best for AdSense approval. It is ultimately up to the discretion of the AdSense team to approve or reject a website for the AdSense program.
However, there are a few factors that can influence the likelihood of approval, and the quality of the theme used on a website can be one of them.
One advantage of using a free theme is that it is generally easier to set up and customize compared to a paid theme. This can be especially appealing for new bloggers who may not have much experience with website design. However, free themes may not always offer the same level of customization or support as paid themes.
In terms of AdSense approval, the most important factor is likely to be the quality and relevance of the content on the website. AdSense looks for websites with high-quality content that is original, informative, and useful to readers. The website should also be well-designed, easy to navigate and have a professional appearance.
Using a high-quality theme can help to create a professional appearance and improve the overall user experience, which may increase the chances of AdSense approval. However, it is worth noting that using a paid theme does not guarantee approval, and there are many successful bloggers who use free themes and still get approved for AdSense.
Ultimately, the key to getting approved for AdSense is to create a website with valuable, high-quality content that is well-designed and user-friendly. Whether you choose to use a free or paid theme will depend on your personal preferences and budget, but it is important to keep in mind that the theme is the only one factor that can influence AdSense approval.
Here are a few options for free themes that you can use on Blogger (also known as Blogspot):