Ancestral Quest is built on the same codebase as PAF and is probably the easiest upgrade path for a PAF user. See their FAQ on Database File Formats.
Ancestral Quest is a commercial product. The full-featured version is a paid product (a one-time purchase, not software as a service), but you could try the free Ancestral Quest Basics. The FAQ discusses the advantages and disadvantages of converting your PAF file to the AQ format, or continuing to read/edit it as a PAF file. Not all of PAF's features will be available, so read the FAQ to see if using AQ Basics would meet your needs.
The Comparison Chart shows the differences betweeen the free and paid versions of Ancestral Quest. You can click a button on that page to include a column of PAF5 features in the comparison.