Its seems very contadictary . How can they get to other galaxies with standard warp drive? Wouldnt they have to be traveling at warp 9.99999999 something

. Also in Voyager's Relativity, Braxtons ship can seeming almost go instantaniously from Utopia Planitia to Voyager in the Delta Quadrent. It a makes it unbelivable the the 32nd century Federation is so dependant on Dillithium Warp Drive.
Warp 9.9 = 4 billion miles per second, which translates to 21 473 times speed of light (this is what we know from what Tom Paris said on-screen).
At that speed, it would take Voyager about 3.5 years to get back to the Alpha Quadrant... but Voyager's hull started breaking apart when nearing Warp 9.9, and they could maybe sustain 9.75 for 12 hours.
The only appreciable top speed Voyager could probably comfortably for extended periods of time would be Warp 9.5 (but Voyager was also in an unexplored area of the galaxy, so the crew couldn't know where they could find needed resources to stock up if they were constantly running at Warp 9.5 or even 9.6 - which is why they usually cruised at Warp 6).
The USS Prometheus was the only SF ship in late 24th century able of hitting Warp 9.9 without suffering structural issues and was also able to sustain it.
Past Warp 9.9, speeds increase exponentially... so for them to reach say Andromeda galaxy in about 4.5 hours, they would need to travel at roughly Warp 9.9999.
Warp 9.975 would give them a speed of about 10 000 Ly's per day (or about 270 days to Andromeda galaxy)... and there are other nearby dwarf galaxies.
We hadn't officially (on-screen) seen that Starfleet achieved any significant breakthroughs in Warp speeds in the past 810 years (which is preposterous in itself) and nothing was mentioned on how fast SF's Warp drive in the 32nd century was.
At best, they may have achieved say Warp 9.96 or 9.975 as a maximum and can get around the Milky Way comfortably... and even potentially reach other nearby dwarf galaxies (the nearest ones being LMC at 179 000 Ly's away and SMC at 210 000 Ly's away).
At 10 000 Ly's per day, they could to LMC in 18 days, whereas for SMC it would take them 21 days.
However, we've seen in Discovery that Admiral Vance mentioned to some SF captains runs to 2 planets... one trip would take about a week or so, whereas the other (for replicator replacements/repairs) indicated it would take 2 months until she came back (so 1 month there and 1 month back at most - and this is assuming that they wouldn't be pushing maximum Warp either but were cruising at a different speed).
Realistically, Voyager's Quantum Slipstream (version 2) topped out at 10 000 Ly's per minute... that would get you to Andromeda in about 4.5 hrs.
The version 1 of Quantum Slipstream didn't require Benamite Crystals and topped out at 300 Ly's per hour (at maximum - for long sustained flights spanning months, the speed dropped to about 740 Ly's per day).
The USS Relativity never went to the Delta Quadrant (that we know of). The ship used temporal transporters to beam 7 of 9 through space and time.
However, the timeship Aeon (Braxton's small ship which Voyager first encountered) was able to generate a temporal rift seemingly in Earth's solar system with an aperture in the Delta Quadrant (70 000 Ly's away) which would technically allow a ship to cross a galaxy in an instant.
The problem with that right was, its temporal technology (Which was banned with the conclusion of the Temporal Wars) in the 31st century (just over 120 years before the Burn) - which seems very stupid to do.. you could just use the technology as a shortcut to travel anywhere in the universe (much like the Spore Drive) but with an in-built modification that prevents it to be used to travel through time (alas, this is unlikely to happen because any and all temporal technology explicitly used to travel through time would likely be banned... including that rift generating technology).
But yes, it IS rather unthinkable that 810 years after 24th century, Starfleet would still be dependent on dilithium and M/AM (or even Warp).
I would have imagined they would have put dilithium and M/AM to the dustbin 25-100 years after Voyager got back... but the writers apparently didn't think that way so we got what we got.