As I have delved deeper into the world of modern grammar, I have noticed frequent references to 'gerund-participial' clauses. Most resources would divide gerunds and participles (past and present) into their own categories, stating that they have different functions. Notably, a gerund can act as a subject or object, whereas a participle cannot. However, I have not seen an accompanying explanation as to why modern grammarians have stopped making the distinction.
I have accepted this new categorisation, but I don't fully grasp the reasoning. Could someone who is knowledgeable about modern grammar explain?