I have a similar but somewhat different view to
@Minigiant . You can’t address exploration unless you figure out what the purpose of exploration is. And the purpose of exploration varies from group to group. Most groups have more than one purpose they enjoy, but probably finds other purpose(s) dull.
Not an exhaustive list:
1. Resource attrition. For some groups, tracking resources and having to deal with the unforeseen is enjoyable. To engage them, you need encounters that force them to use resources that aren’t easily replenished on a long rest. Make diseases longer lasting and more debilitating. Create new conditions that don’t disappear on a long rest. Damage or destroy equipment.
2. Flavour. Some groups like exploration encounters for what they say about the world. In the middle of a long trek through the Mourn land, the party comes across a massive warforged. Or a peddlar shares their food and regales tge party with stories. Nothing is really at stake, but it’s fun and gives the party a chance to improvise. Doesn’t require mechanical changes apart from avoiding the rote “you come across a chasm with the rope bridge destroyed”.
3. Resource generation. Say you are running a more domain focussed game. The party may not care about encounters that tax their resources or encounters that exist for world-building purposes, but they will care that a particular hex contains an iron mine they can develop. Or a pool they can drink from once per month that grants 10 temp hp.
4. Obstacle. Far too many pre-made exploration encounters fall into this category, but it has its place. The trick to an obstacle is that it has to be meaningful. There are very few obstacles that can’t be overcome if you take sufficient time, so give the party a reason to hurry. You need to bring the flower that cures lycanthropy to the village in the next 3 days! Now, deciding to risk an obstacle or take the time to go around it becomes a choice.
5. Side quest/adventure hook. Some parties mainly like exploration encounters because they open up the world by creating or giving space to new adventures.
My point is that even non-resource attrition oriented parties can enjoy exploration encounters so long as those encounters address the aspects of the game they enjoy. Conversely, even resource attrition oriented parties will find exploration encounters a drag if they don’t actually impact the resources they have at their disposal.