How do you destroy magical objects?

Artifacts can only be destroyed by a special way. Weaker stuff will require less drastic stuff. You could hit a magical gem with a hammer a couple of times and it would brake. The Volcan trick will work too.

Can you break a magical weapon 5e?

So, besides artifacts all magic items are broken like anything else, just that they have resistance to all damage. This is basically so they cannot easily be broken, and most likely since it’s intended that they cannot be easily repaired.

Is it true that matter cannot be created or destroyed?

That “matter cannot be created or destroyed” is a lie told to kids in high school chemistry to help them with balancing chemical reaction equations. The truth is that matter is created and destroyed regularly in, for example, particle physics. Sorry about that. In a black hole as modeled by classical General Relativity, matter just disappears.

Can you make more than one net attack?

Without feats it appears He will always be at disadvantage with the Net attack and the Net states you can only make one attack if you use the net even if you have multiple attacks. Restrained is a strong thing at lower levels for sure, not sure how well it will scale.

What makes a net too resilient in dungeons and Dragons?

One thing to note about making net too resilient is its actually kinda powerful. It applies the restrained condition, which gives the target disadvantage on almost everything until they either attack it (with disadvantage) or break it. Either way they had to use their action and spent a turn granting advantage on all attacks.

Are there any quibbles with nets in dungeons and Dragons?

My main quibbles with nets is that it removes your extra attacks and that the net will probably be destroyed if the target has anything that can deal slashing damage. This means that you either walk around with more than one net, or can only count on getting one use out of it.