My two cents on classes:
Thief: As mentioned above, lowest party utility. But it hits hard. High burst with stealth/backstab and high sustain dps with dagger auto attack. Good amount of evades, blinds. But has low HP pool and is squishy. Dies very easily if you don’t have good knowledge of content.
Revenant: Much more durable than thief as it has higher base hp pool and wears heavy armor. Great party boon support through facets. But imo has an incredibly boring gameplay where your dps comes from autoattacking with sword for ages.
Warrior: Very straightforward and simple dps class where you just run in and smash things with a greatsword or axe. Fairly high dps. Highest hp pool and heavy armor makes warrior very durable, therefore lots of room for errors. If specced for phalanx strength, warrior has unparalleled might sharing for party. Warrior strength and discipline banners are also invaluable in terms of party support. Due to its capability of providing amazing party dps support, warriors/berserkers are always welcome in parties. Just can’t go wrong with one. Pretty much have to go with zerk gear on warrior these days. When they first came out, condi berserkers were just brokenly powerful. Then Arena Net nerfed them to the ground so hard they are no longer viable.
Guardian: Sort of like warrior, but has much higher learning curve. Has extremely high burst dps with greatsword and traps if running dragon hunter spec. Can be specced to do amazing party support, but meta more or less dictates guards to go full zerk gear. While being frontline class guard has the lowest hp pool alongside elementalist and thief. Guardian has to make good use of aegis and blinds to survive. Very important to know fights/when to dodge/pop aegis/pop blind, etc. Not much room for error.
Elementalist: Very squishy, but arguably the highest dps class. The tempest spec with fresh air trait makes elementalist a dps machine. Ele is also an extremely versatile class that can be specced to perform dps or party support roles. Not much room for error due to lowest hp pool and light armor. Have to be quick with fingers and know fights in and out.
Necromancer: Light armor class, but highest hp pool alongside warriors. Despite being light armor, they are one of the tankiest classes because of their shroud ability. Necros can be great dps classes if specced for zerk gear. Zerk reaper can do some great damage, but for high level fractals or raids where bosses have a lot of dmg resistance/physical dmg defense, condi reaper is much better. Condi reaper requires viper gear, which is incredibly expensive to craft. But it is satisfying seeing 15K+ bleed and 5K+ poison per tick on a boss.
Engineer: Medium armor class with decent hp pool. Vanilla engi’s usefulness has somewhat diminished after the scrapper spec was released with heart of thorn expansion. Scrapper forces engi to adhere to a “in your face melee” style, but it is worth it because zerk scrapper does some holy moly dmg. Due to the toolbelt mechanic, scrapper engi is somewhat complicated to play, and you need to be very quick with your fingers.
Mesmer: medium high hp pool with low armor. No matter what you do, mesmer dps will be lackluster. Vanilla mesmer, similar to vanilla engi, has diminished value to parties these days because it just doesn’t do much. However, the elite spec chronomancer mesmer is invaluable to parties because it can provide a boon that no other class can- alacrity. Alacrity makes all party members’ skills recharge 33% faster. Along with certain skills that provide quickness, chronomancer can shave off a good chunk of time off of a boss fight with the support they bring.
Ranger: Medium hp, medium armor class. They don’t particularly excel in the dps department as you found out, but honestly their dps isn’t terrible either. If you want to talk about terrible dps, you just have to take a look at mesmer. Ranger’s strength lies more in party support. Vanilla ranger has diminished value after heart of thorns release, but frost spirit and spotter are still a great additions to any party. If specced for druid, rangers can dish out unparalleled healing capabilities, which makes them valuable for raids, wvw, or even pvp (druids are like immortal in pvp).
Think I will try a thief for a little.