Yet we lost approximately the same number of airplanes in the ETO every month from Sep 44 thru Apr 45 except for Mar 45 when we lost more. The effect of the Luftwaffe didn't change, almost at all, until May 45, and VE day is 98 May 45.
Army Air Forces Statistical Digest World War II
Table 159 — Airplane Losses on Combat Operations in European Theater of Operations, by Type of Airplane and by Cause of Loss: Aug 1942 to May 1945
(p.255 of the report; p.276 of the PDF)
Only Jan. 1944 through April 1945 are presented for brevity's sake. The first figure is the number of heavy bomber aircraft lost to enemy fighters; the second is the number lost to flak; the third figure is the number lost to other causes; the figure after the equal sign is the total.
139 +
027 + 37 = 203 — Jan. 1944
170 +
081 + 20 = 271 — Feb. 1944
178 + 112 + 55 = 345 — Mar. 1944
314 + 105 +
01 = 420 — Apr. 1944
211 + 122 + 43 = 376 —May 1945
112 + 162 + 46 = 320 — June 1944
080 + 201 + 71 = 352 — July 1944
061 + 238 + 32 = 331 — Aug. 1944
137 + 207 + 30 = 374 — Sept. 1944
036 + 112 + 29 = 177 — Oct. 1944
050 + 146 + 13 = 209 — Nov. 1944
028 +
074 + 17 = 119 — Dec. 1944
049 + 222 + 43 = 314 — Jan. 1945
014 + 157 + 25 = 196 — Feb. 1945
063 + 164 + 39 = 266 — Mar. 1945
072 +
077 + 41 = 190 — Apr. 1945
001 +
004 +
02 =
007 — May 1945
These figures demonstrate your overall statement is not accurate (I would not classify 119 or 177 as being approximately the same as 374 or 314).
Additionally, the number of heavy bombers lost to enemy fighters drops significantly after April 1944. (Indeed, April of 1944 was the highest monthly loss to enemy fighters in the ETO of the entire war.) If we divide the years into thirds, from Jan.–Apr. 1944 there were 801 heavy bombers lost to enemy fighters; from May–Aug. 1944 the number dropped to 464; from Sept.–Dec. 1944 the number dropped to 251; and from Jan.–Apr. 1945 the number decreased again down to 198.
Clearly, the ability of the Luftwaffe to shoot down U.S. bombers peaked in April of 1944 and fell off markedly after that.
Flak losses, on the other hand, went up. From Jan.–Apr. 1944 there were 325 heavy bombers lost to flak; from May–Aug. 1944 the number rose to 723; from Sept.–Dec. 1944 the number dropped to 539; and from Jan.–Apr. 1945 the number increased to 620.