Chain is very heavy but the major advantage is the excellent chafe protection.
Even in relatively deserted anchorages it sad to see how much rubbish is on the seabed. Old moorings, engines, sewing machines etc etc. When encrusted with sea growth this type of debris is sharp enough to cut through rope quickly. Then there are natural hazards. It is not unusual to see isolated patches of rock in predominant sand or mud anchorages. Coral areas are particularly bad. Naturally you want to avoid anchoring in areas of live coral, but there are frequently large sharp lumps of dead coral on the bottom of many anchorages, so cruising in coral waters is difficult without a reasonable amount of chain.
The other problem is encountered in very crowded anchorages with other cruising boats. Nearly all long distance cruising boats will be using an all chain rode and if you want to use predominantly rope rode you will swing significantly differently.
This does not mean that you need a long length of chain to cruise, but it does make things safer by largely eliminating any concern about chafe.
If you are managing with only a smallish amount of chain one option that can be used is to adjust the length of rode as the wind strength changes so the rope portion is always above the seabed where it safe from chafe. If you have a small amount of chain this will mean adjusting your scope to quite low values if the wind is light. Providing there is some chain on the bottom this will not have much impact on the holding ability, but you need to prepared to let out more scope as wind rises.
The other option is to use G7 chain, which enables a smaller size to used for the same strength, but this has some other drawbacks. There is also the possibility of using Dyneema or Acera that have much better chafe resistance that other fibres that are traditionally used for rope rode, but once again these are not without problems. The chafe resistance is still significantly worse than chain.
In this type of situation rope rode will not last long: