I would rather call it a partial success, even though not all the goals of the operation have been achieved.
Whereby that comes are different reasons for it.
First, there was the grounds.The Allies had to pull with tanks over narrow dyers and over many bridges. In both places they were easily targeted for the Germans. It was not only at Arnhem that there was heavy fighting, but in several places on the route. It was easy for the Germans to ambush the allies along the route.
Secondly, there was the weather that was disappointing.The parachutists were not allowed to leave at any moonlight because of policy, so the landing was postponed, which gave the Germans the opportunity to prepare for a new battle. The troops could therefore be supplemented with SS divisions near Arnhem.
Thirdly, there was problems with logistics.The port of Antwerp was not yet properly usable as a supply point. Also the British did not have enough gliders available to be able to do the drop at one time.
Fourthly, there was a poor preparation of the Allies.The reason the Allies wanted to implement Montgomery’s plan was to deal with the V2 missiles that were still fired on English cities from occupied Netherlands. The reason for Montgomery to implement the plan prematurely had to do with his own tunneling of his perception caused by unrest and the underlying reason for that was probably Asperger syndrome.
Despite the heavy losses of the British and Polish Division and despite the fact that one did not pass Arnhem, the Germans also suffered heavy losses and lost a lot of terrain and material.The SS division lost quite a few tanks, which were no longer replaceable for the Germans. Many of them have been eliminated by a major WITH a piat still though.
Only when the supply improved, because Antwerp could be used after the Battle of the Scheldt, the Allies managed to get past the Rhine.That happened at Remagen.
A big problem was that there was a SS battalion lying along the river that was stationed there to relax after a period on the Eastern Front.They came to action very quickly when they suddenly had to deal with an air landing operation.
I would not say that it was not a success for the Allies.Except Arnhem, every goal was achieved.
The fact that Arnhem was not met is by: 1) Arnhem was just too far away, which was a stark underestimation of Montgomery; 2) The Allies had only one way over which they could snatch-very easy to defend; 3) The English paratroopers had the misfortune that just in the area where they were down, at that time, two hardened SS armored divisions were resting during a battle break from the Eastern Front; 4) The landing sites were too far away from the bridge, the purpose of the landings; 5) Nijmegen is a notoriously difficult place to conquer, especially the bridge over the Waal-that had already encountered the Germans in 1940, and they had only the Dutch army opposite-it was again a stark error from Montgomery So that the advance to Arnhem was too slow.The advance through Eindhoven, Brabant and Grave went almost entirely according to plan, only at Nijmegen, where one arrived quite late was too much time to be able to be still in time in Arnhem and to relieve the paratroopers; and 6) bad material, logistical problems, poor communication and the like.
The Germans were unaware of the attack in advance, though at some point the attack plans were found for Market Garden, only those were not taken seriously by the Germans, who took the view that it was a sting operation to field Marshal Model captured.But that was only as long as it was not yet aware of the other attack that started from Belgium.
There is a movie, which you have to look at: “A Bridge Too Far”.I do not want to say that 100% is historically accurate but then you have a very nice idea.