Seems like it's being addressed in that "Readers added context" community note present in the embedded tweet...
Besides... All it would have taken for Lindberg to be completely wrong at the time he said that in 1940, would have been for the Allied side to get the Soviet Union to enter into the war against the Axis powers. Could the Allied side have succeeded in persuading the Soviet Union to join them even if Hitler hadn't broken the non-aggression pact?... That we will never know.
EDIT:
But I'm going to wager a guess that the threat of the Nazis succeeding in developing an atomic weapon before the Allies would have been a 'rather persuasive' motivator...
The situation between the UK and Germany was not all that unlike Ukraine and Russia today. The British controlled the Atlantic, but Germany was making a play to neutralize that with u-boats. Britain's capabilities in anti-submarine warfare were advancing at a high rate. What ultimately turned the tide were escort carriers. The US built over 100 of them in Vancouver, WA and gave a bunch to the UK via lend lease. Without the US in the war, the US could have still given Britain the carriers.
The two air forces were pretty evenly matched. By the end of 1940 Britain could control it's air space completely in day time and Germany had to operate at night. British night fighter technology was coming along and would have been inflicting high casualties on the German night bombers by late 1941 if the Blitz hadn't ended.
Germany was more powerful on land, but they didn't have the lift capability to get their troops to England. For the 1940 invasion they had cobbled together every barge they could find, which would have made the channel crossing treacherous. River barges are not designed to handle open water.
The Germans also assessed they couldn't invade England without controlling the air and neutralizing the Royal Navy, both of which were beyond the reach of their forces. The Battle of Britain was an attempt to neutralize the RAF and it failed. During the battle the RAF grew stronger while the Luftwaffe grew weaker.
By the end of the battle Britain was producing more fighters than they were losing and they had stepped up their pilot training significantly. Britain also maintained their pilot rotation program throughout the battle so there was always a cadre of experienced and rested pilots. Germany was not rotating their pilots and by September 1940 they were exhausted. Because Germany was on the offense any aircraft shot down resulted in the loss of an air crew even if they survived while anybody who was shot down and survived on the RAF side was preserved. If injured they might be sent to training command to train up the next generation of pilots, but if fine, they would be put back into a plane and put into the air again.
The Commonwealth didn't have the manpower to defeat Germany on the European continent. That took countries with larger populations. However, they did have the ability to keep Germany in check pretty much indefinitely.
The Commonwealth and Germany had roughly the same manpower available, but the Commonwealth had that manpower spread out across the globe. Britain had many overseas possessions that needed to be protected. Britain also had one of the largest navies in the world that soaked up a significant portion of their manpower. Germany had a very small surface navy, and was a continental power with the bulk of their manpower in the army. Germany also didn't have any possessions outside Europe so they could concentrate their ground forces more than the Commonwealth could.
In the current war Russia has more people, but their available manpower is sapped by trying to maintain an economy and maintain a massive land empire. Because of civilian resistance to the war, they are limited in how many men they can call up at a time. A general mobilization of all men of military age would both crash the economy and lead to massive riots. Ukraine has 1/3 the population, but they have shut down most of the civilian economy. 1/3 of their GDP is pouring into the military. The largest spending of any country on Earth by a large margin.
Even with US aid suspended, they are holding out. Advidivka is being taken by the Russians, but at an astronomical cost. If they took ground at this rate all the way to Kyiv Russia would lose multiple times its entire population getting there. Russia is suffering huge losses just as the Luftwaffe did in the summer of 1940. They are not sustainable losses long term.
The goal of this war is more achievable than the Commonwealth's goal in 1940. The Allies drove all the way to Berlin and destroyed the Third Reich at its heart. The goal of the current war is to get Russia off Ukraine's territory. Ukrainian tanks are not going to be in Red Square at the end of this.