It really varies from person to person. Studies have shown that only about 16% of women can cum from penetration alone, but that number may be skewed by men who, in one way or another, don’t do what’s required to make it happen. Some women can cum but it takes a while, so they can do it with a dildo but not a man who has a time limit before he either cums or runs out of energy, or just haven’t been with a man who puts in the effort to get her aroused enough beforehand, or men who can adapt their stroke technique to her anatomy, or just don’t listen when she tells them what to do, or women who are socially conditioned against communicating their needs and think they need to just take whatever the man thinks is right. This makes it difficult to determine whether or not any given woman can’t cum at all from penetration alone or just hasn’t experienced the things necessary to make it happen.

This is why communication, active listening, and adapting your form to suit your partner are important to maximize pleasure for all parties involved.