I think the original idea of material components is to "cost a hand slot".
So if you're a wizard or sorcerer, keep a hand free all the time and stop worrying. Most mages don't use shields, so in older editions it was mainly a choice between holding a weapon in the other hand vs being the torch-bearer, holding the map or similar. Many mage-types in 5e don't even use weapons because they have attack cantrips, so it's even easier.
There will be exceptional cases like if your hands are tied, gripping/holding on to something etc. so you'll have to make a choice.
Then of course people will always argue that they want to pass an object to the other hand, hold two objects while you cast, use a leather strip to drop the weapon without having to pick it up... I hate those debates. The rule is there to force a strategic choice as if your hands are a limited resource. If your group doesn't like it, IGNORE it and move on. Otherwise use the rule and don't cheat.
A reaction on the other hand doesn't take a specific amount of time, so even by the rules you are not supposed to worry about how fast you need to reach for a material component, just "spend" your reaction and the rules abstraction have you covered.