The recent trade between the Phillies and the Angels is being perceived as a bad one in the eyes of many Angel fans. The swapping of two relief pitchers is not the kind of deal that can make or break a season. In 2018, Jose Alvarez pitched 63 innings which accounts for roughly 4.3% of the total innings thrown by Angels pitchers. That's not a ton of innings, and he would be expected to hold a similar workload in 2018. Ideally we would not give those 4% of innings to a worse reliever, and in the case of Garcia we are not.
There seems to be a misconception about Garcia that he is worse due to his high ERA in 2018. If you're exclusively looking at ERA then sure you can say that in 2018 Alvarez was better than Garcia. However, if that is your line of thinking then you are completely off base from what Major League front offices are looking at when evaluating players. ERA is a poor indicator of future pitcher success, and looking at numbers like BB's and Strikeouts do a much better job at showing how that player will fare in the future.
To get a larger sample of both players lets take a look at their last two years:
Alvarez: 111.2 IP, 22.4% K%, 7.3% BB%, 0.8 HR/9, 3.98 xFIP
Garcia: 117.1 IP, 22.2% K%, 8.8% BB%, 0.5 HR/9, 3.79 xFIP
As you can see there is not a huge difference between the two when looking at their ability to miss bats. xFIP is a much better indicator of future success than ERA. On the surface they look completely different, but when you start digging into the numbers you notice that there is not much of a difference between them.
The biggest worry seems to be the loss of a lefty in the pen, and this is a strong point. Alvarez is left handed and is good against left handed hitters. In the 2017-18 sample, Alvarez posted 64.1 IP, 8.4 K/9 and 1.4 BB/9 with a 3.63 xFIP. Garcia was not good against left handed hitters, posting 49.1 IP, 6.9 K/9, 3.8 BB/9 and a 4.10 xFIP. Not great, but as you can expect Garcia was better than Alvarez against right handed hitters. 68 IP, 9.7 K/9, 3.0 BB/9 and a 3.57 xFIP for Garcia. 47.1 IP, 8.4 K/9, 4.6 BB/9 and 4.45 xFIP for Alvarez.
Essentially, this trade is swapping Alvarez's handedness and the name on the back of his jersey. Leaving the team without a quality left handed option out the pen is troubling, but there are plenty of quality left handed options on the free agent market. Andrew Miller, Zach Britton, Jake Diekman, Oliver Perez and Justin Wilson all come to mind. At the end of the day, even if Garcia is worse than Alvarez it will not be the end of our season. At the end of the day, this trade does not matter that much. There is no reason to believe we are throwing the season away because we traded a relief pitcher (not even our best one) on December 6th.