Is it typical to have write speed halved by RAID0 (with lvm2), and what can I do about it?

Since I configured two SATA SSDs as a RAID0 with lvm2, Disks (gnome-disk-utility) reports in its benchmark that their reading speed is around doubled, but their writing speed is halved. Screenshots attached. Is it as expected? Or how can I troubleshoot/fix that?

The two SSDs are a Samsung 840 EVO and a Samsung 850 EVO. Running Ubuntu 22.04.1

-> sudo pvscan
  PV /dev/sda   VG sata_ssds       lvm2 [232,88 GiB / 0    free]
  PV /dev/sdb   VG sata_ssds       lvm2 [232,88 GiB / 0    free]
  Total: 2 [<465,77 GiB] / in use: 2 [<465,77 GiB] / in no VG: 0 [0   ]
-> sudo lvs --segments
  LV    VG        Attr       #Str Type    SSize   
  raid0 sata_ssds -wi-a-----    2 striped <465,77g
-> sudo lvs -a -o name,copy_percent,devices sata_ssds
  LV    Cpy%Sync Devices                
  raid0          /dev/sda(0),/dev/sdb(0)
-> udisksctl  status
MODEL                     REVISION  SERIAL               DEVICE
--------------------------------------------------------------------------
Samsung SSD 980 PRO 500GB 5B2QGXA7  S5GYNX0T708561R      nvme0n1 
Samsung SSD 980 PRO 500GB 5B2QGXA7  S5GYNX0T708613K      nvme1n1 
Samsung SSD 840 EVO 250GB EXT0BB6Q  S1DBNSBF835020A      sda     
Samsung SSD 850 EVO 250GB EMT02B6Q  S21PNXAG665086W      sdb     
TOSHIBA HDWD120           MX4OACF0  58QZRRGCS            sdc     
JMicron Tech              0209      DD564198838AA        sdd     
Generic MassStorageClass  1536      000000001536         sde     
Generic MassStorageClass  1536      000000001536         sdf     

Before RAID0

With RAID0