Hi! In my opinion custom portraits can look great as wall decor because they combine personal meaning with artistic style. I recently ordered one based on a photo from a trip and it turned out to be one of the most interesting pieces in the room.
While researching options I discovered https://www.popartyou.com/ where artists create custom made portraits from photos. The idea is that your image is transformed into artwork that still keeps the recognizable features of the original photo. Because of that, it feels both decorative and meaningful.
Many people use custom portraits as part of their interior design because they add personality to the space instead of looking like generic posters.