Xaelvaen
Stuck in the 90s
One of the key mechanics of D&D over the years has been the idea of resource-draining encounters. You burn torches, you fire arrows, you lose hit points to swarms of mooks, you cast spells from encounter-to-encounter, you scrape by with just enough strength left in you to fight the Big Bad at the end of the dungeon. Or you camp in a "safe area," hoping your characters can recover their resources without random encounters that further drag out the game and spend more resources.
Herein is the problem (for me). My group gets together twice a month, if we're lucky. We get about 3 hours of "quality" time each session (after taking out breaks, snacks, general socializing, etc.) Knowing that the majority of our time is going to be spent with "another ho-hum goblin encounter that will only challenge us by spending a 1st level spell and a few arrows" or a trap that might do 1-6 hp of damage, it just doesn't seem a good way to spend time.
Any one else experiencing this? Any work-arounds?
I don't experience the problem in the same way as you, in that we play weekly - however, there are similar situations that arise for different reasons; mainly, we've been playing for 20 years, and you have to continuously keep it fresh and interesting. Here's a few things that I use. While they may not be ideal for you and your party, I hope it helps:
1) Glass Cannons: I create my own monsters to be very low in Hit Points when the battle needs to go quicker, but pack a far deadlier punch than their durability might otherwise portray. This allows a lot of damage to be inflicted onto the party early, and you create a sense of 'edge of your seat danger' right off the bat. The enemies die quickly, which means that the damage output goes down very rapidly, and the battle becomes quicker with each passing round. Bugbears are a great example of this, provided they start the battle hidden, of course.
2) DMG alternate - 5 minute Short Rests: We found that we go without magical healers more often than not when we play 5E. Hit Dice healing is absolutely necessary. So instead of players worrying about that hour of time to recharge their abilities and heal, we just made it so you can do that right after every battle. It creates a sense of automatic memory and players can do this very expeditiously, saving not only time 'in character' but also time in reality.
3) Success at a Cost: When a player just barely misses a target number (attack roll, skill check, saving throw, etc.), I give them the option of succeeding anyway, but at a cost. This decreases the number of wasted turns and lets the combat go a bit faster, at least as far as the players feel. The cost is up to you. (At my table, we use GM Tokens. When a player wants to succeed at a cost, the GM gets a token. The GM can spend these tokens to add +1d6 to any d20 roll a badguy makes.)
4) Round Time Limit Bonus: I have a 1 minute stopwatch behind my DM screen. On each player's turn, they get 1 minute to complete their turn, including all dice rolling and information conveyance. If they take longer, that's okay - no one is punished. But if they are done within the minute, they get a bonus on whatever action they took for the round. The players know this, so they try to work together off-turn, plan and strategize, and get their things organized better for each round. A lot of the time I make that bonus +2 to the attack (if they need it to hit), or +5 damage. Again, this makes things go much faster, and encourages teamwork and communication.