The big problem with multiple partitions is that no matter how much care was used in selecting the sizes one partition will often prove too small while others have space to spare. Even experts get this wrong. With folders the file system will distribute disk space as needed.
Many people have one partition for the OS and applications and another for data. The OS can then be reinstalled without touching your data. But if you maintain regular backups (as you should) that will not be a big issue anyway. But doing this requires that you make many decisions as to where specific data will be stored. Many people have created a secondary partition, accepted the defaults for everything when saving files, and find that the OS partition is almost full and the other nearly empty. It takes planning and self discipline to avoid this. People who do this successfully have learned from experience, making many mistakes along the way.
Most people are best served with a single partition. Many systems will have other partitions created during OS installation and I do not include these.
Also understand that before repartitioning a drive containing data you should have a full backup of everything on the drive in the event that something goes wrong. This is unusual but it does happen.