Are XC bikes good for beginners?

Yes, particularly hardtails. They are the most affordable entry point to mountain biking, teach good bike handling skills (because there's no suspension to mask mistakes), and are efficient enough to build fitness. However, beginners riding technical terrain may find XC bikes intimidating on descents. If your local trails are steep and rough, a trail bike may be more confidence-inspiring despite the higher cost. For most beginners on moderate terrain, an XC hardtail is an excellent starting point.